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Home , Anthropologist, Biological anthropology, Humanity (journal)

Evolutionary 21:182–194 (2012)

ISSUES

What Makes Us ? Answers from Evolutionary Anthropology

JAMES M. CALCAGNO AND AGUSTI´N FUENTES

With contributions by: Matt Cartmill, Kaye Brown, Katherine S. Pollard, Robert Sussman, Robert M. Seyfarth, Dorothy L. Cheney, Benjamin Campbell, Sarah Hrdy, Kristen Hawkes, Karen R. Rosenberg, Mary C. Stiner, Steven L. Kuhn, and Ken Weiss

Today, scholars from numerous and highly diverse fields are not only address- enough to respond to the question of ing the question of what makes us human, but also seeking input from other dis- what makes us human. Individual per- ciplines to inform their answers to this fundamental issue. However, for the most spectives include , behav- part, evolutionary are not particularly prominent in this discus- ioral , human , neuro- sion, or at least not acknowledged to be. Why is this the case? One reason may anthropology, , be that although evolutionary anthropologists are uniquely positioned to provide and . No instructions were valuable insight on this subject, the responses from any one of us are likely to provided other than to answer the be as different as the research specializations and intellectual experiences that question in 800 words or less. In addi- we bring to the table. Indeed, one would anticipate that a paleoanthropologist tion, no one else knew who the other would not only have different views than a primatologist, geneticist, or behavioral contributors were, to avoid any temp- ecologist, but from other paleoanthropologists as well. Yet if asked by a theolo- tation to respond in ways that might gian, , or political , and perhaps most importantly, by any anticipate another author’s com- curious person outside the walls of academia, do we have a response that most ments. Thus, individual essays were evolutionary anthropologists could agree on as reflecting our contributions to the not expected to conform to others’ understanding of being and becoming human? Our introductory textbooks usu- views in any way and were written ally begin with this fundamental question, yet seldom produce a concise answer. entirely independently of each other. Given that conflicting views were not only expected, but indeed welcomed, In this series of brief essays, we we conclude with our own commen- James M. Calcagno is Professor of An- attempttoprovideinsightintothepossi- tary distilling any common ground thropology and Fellowship Office Director reached in the 10 essays that follow. A at Loyola University Chicago. His research bility of a coherent evolutionary anthro- interests in have pological answer to what makes us priori we reserved the right to regard ranged from mechanisms of dental reduc- human. We recognize that this simple, some specific points as better than tion to captive behavior. In 2009 and 2011, he co-organized Wiley-Black- basic question is actually tremendously others. well AAPA symposia directly relating to the complex. Yet if we continue to tout in Although depth and breadth are question ‘‘What Makes Us Human?’’ laudable and needed when discus- Email: [email protected] our classrooms the importance of evolu- Agustı´nFuentes is Professor of Anthropol- tionary anthropology in understanding sing any complex subject, we seek to ogy at University of Notre Dame. His cur- humanity, it seems unwise to avoid produce a brief answer that almost rent research includes cooperation and community in human , ethnopri- direct attempts to answer the question everyone in the field could agree on matology and multispecies anthropology, of such great interest outside our disci- as hitting key points, and from evolutionary theory, and interdisciplinary approaches to human nature(s). Recent pline. Our individual research efforts which curious outsiders to the field books include Evolution of Human Behav- are, by necessity, more narrowly could easily consume and benefit. ior Biological Anthropology: Concepts and focused, and may contribute a piece of This may be an impossible task. If Connections,andRace, , and Other Lies They Told You: Busting Myths insight toward the question but not an- so, perhaps greater attention is About Human Nature. swer it. We propose that evolutionary needed regarding the effectiveness of Email: [email protected] anthropologistsshouldstepoutsideour our discipline in connecting with a normativepracticetotakeonthisbroad much larger audience. We hope that and societally relevant question. This fo- you will read these essays with an VC 2012 Wiley Periodicals, Inc. rum is a start. open mind. We are interested to see DOI 10.1002/evan.21328 Published online in Wiley Online Library We have assembled 13 distinguished whether or not you agree with our (wileyonlinelibrary.com). evolutionary anthropologists bold conclusions. ISSUES 183 Being Human Means that ‘‘Being Human’’ Means Whatever We Say it Means

MATT CARTMILL AND KAYE BROWN

What makes us human? This ques- have been shifting toward our ‘‘proso- superstition, it gives us adaptively val- tion can be read in several ways. It ciality.’’ now tell us that uable insight into the intentions of our might be an empirical question about are innately disposed to sacri- friends, enemies, predators, and prey. what distinguishes humans, like ‘‘How fice themselves to help others, and Both sadism and compassion are do you know this is an emu?’’ This one apes are not. In recent , this grounded in this faculty of projection. is easy. We all know how to identify supposed human peculiarity has been People may be the only animals that humans: (1) upright bipeds with (2) predicated of everything from allomo- find it rewarding to share with and nimble hands, (3) big brains, (4) short thering to projectile weapons, and help their own and other species; but faces, (5) weird pelage, (6) protruding hailed as the foundation of language, they are also the only animals that find fat depots, and so on. We like to stress social norms, and morality. But this it rewarding to inflict gratuitous pain. traits 1–3 because we associate them ignores 50 years of sociological Being human means that as well. with having power over nature, but research that indicates that it takes Our capacity for projection may have the others would be equally useful in socialization — of the right kind — to direct neural correlates, but it also 1 keying out a specimen. overcome the innate selfishness of depends on language. Dunbar argues We believe a different question is children. That contradiction needs to that while many animals have ‘‘first- being asked in this symposium — be addressed. The experiments sup- order intentionality’’(readingtheirown namely, ‘‘Which of our peculiarities porting the prosociality idea also need thoughts) and a few have second-order give humanity its unique importance more comparative depth. Many sup- intentionality (‘‘theory of mind’’), and significance?’’ This question is posedly innate human traits pro- human brain structures allow us to not empirical. Since humans decide claimed by experimenters have turned achieve sixth-order intentionality in what words mean, we can draw the out to be peculiar to Western elites. exceptional individuals, such as Shake- animal-human boundary as we wish, Two genuinely pan-human traits speare. Dunbar would have us think that in writing Othello,Shakespeare give it any meaning we wish, and may explain many of the phenomena intended his audience to understand change both whenever we like. currently attributed to innate human that Iago wants Othello to believe that The meaning, markers, and justifi- prosociality. The first is our unique Desdemona knows Cassio loves her. cation of human status have fluctu- propensity for imitation. Humans are This, Dunbar says, is sixth-order inten- ated throughout Western . the only terrestrial mammals that tionality, beyond which the human Language has generally been viewed imitate sounds, and the only animal mind cannot go. We doubt this, because as a crucial marker — so crucial that that imitates the things we see. Lan- we went one level further two sentences linguists change their definitions of guage, art, dance, and every aspect of back and could go further still. This sort language whenever rudimentary lin- human socialization depend on this of nested ‘‘intentionality’’ appears to us guistic capacities are discovered propensity. We suggest that preverbal to be a byproduct of syntax (sentence among nonhumans. Lately, concep- imitation, beginning with mother- embedding), not neocortex volume. tions of the defining human excellence infant pairs, is the foundation of all Some argue that humans are objec- social learning in humans. Cultural tively important because of our huge Matt Cartmill’s writings and ongoing homogeneity arises first from imita- biomass and ecological impact. How- research deal with primate origins and tion, not from some innate, prosocial ever, these are not properties of our spe- phylogeny, comparative cranial and evolution, , locomotion, tendency to internalize norms and cies, but of the co-evolving agricultural the history and of science, values. Social norms and values are symbiosis of which Homo sapiens is the and the biological correlates of lan- inculcated mainly through language, CEO and chief personnel officer. With- guage, morality, and consciousness. His most recent book is The Human Lineage which requires the faculty of imita- out our domesticates and their huge (with Fred H. Smith). He currently serves tion. Therefore, we believe that imita- biomass, Homo would still be a rare on the faculty of Boston University and predatory primate. All we can boast of the emeritus faculty of Duke University. tion must precede normative behav- Email: [email protected] ior in ontogeny — and, we suggest, in uniquely is that we are the ones who Kaye Brown developed and administers hominin phylogeny as well. have to make the decisions that will pre- the BU Dialogues in Biological Anthropol- ogy, a filmed conference that spotlights The second is the human capacity serve this symbiosis or bring it crashing current debates in the field. She writes on for seeing things from the other fel- down — and us along with it. topics in architectural gerontology, social movements, and physical anthropology, low’s perspective. Humans are so and annually develops the national student strongly disposed to understand the REFERENCE design for long-term care motivations of others that we are 1 Dunbar RIM. 2007. The social brain hypothesis administered by AIAS. She serves cur- and its relevance to social . In: Forgas rently on the faculty of Boston University. always seeing motivations where they JP, Haselton MG, von Hippel W, editors. Evolu- Email: [email protected] do not exist. Although this disposition tion and the social mind. New York: Psychology encourages anthropomorphism and Press. pp. 21–32. 184 ISSUES The Genetics of Humanness

KATHERINE S. POLLARD

What makes us unique as a spe- contributed to uniquely human func- gle-base mutations. These dynamic cies? From a genetic perspective, the tions. However, these genes explain regions likely harbor much of what answer is ‘‘Not very much.’’ Sequenc- only a small part of what makes us makes us genetically human. ing of the human and human. As novel technologies enable us to genomes allowed us to line up our In contrast, there is mounting evi- study a wider range of molecular DNA against that of our closest living dence that mutations in gene regula- data, geneticists will be digging even relative on the tree of life and take tory sequences affecting when our deeper for what makes us human. stock. We found that the human and proteins are expressed play a major Sequencing hundreds of living and chimp genomes are nearly 99% iden- role in human-specific , as extinct human genomes will help to tical and that each changed about hypothesized several decades ago.3 pinpoint the genetic changes that the same amount since our common Studies in a variety of different organ- make us modern humans, in contrast ancestor.1 To put this difference in isms support the importance of regu- to those that distinguish hominins as perspective, a mouse and a rat differ latory mutations in the evolution of a group from chimps and other at about 17 out of every 100 bases.2 closely related species.4 Similarly, . Another new direction Humans are not especially fast many of the fastest evolving sequen- involves studying epigenetic changes, evolving. Instead, it appears that a ces in the are outside including losses or gains of chemical 5 few key changes in the right DNA of genes in regulatory DNA. These marks on the genome and the asso- sequences had big effects, modifying uniquely human regulatory sequen- ciated proteins that affect gene traits such as bone morphology, ces, called Human Accelerated expression without altering the DNA 6 dietary repertoire, and disease sus- Regions (HARs), are located near and sequence itself. Further expanding ceptibility, all of which distinguish likely control a very important collec- the concept of the genome, studies humans as a species. So where are tion of genes, many of which are of may soon these high impact mutations? involved in development and human include analyses of DNA from all the Because proteins are so important disease. Because many of the genes microorganisms that live in and on for cellular functions and the genes with HARs are transcription factors our bodies. It will be interesting to that encode them make up only a that control the expression of other see if any of these broader defini- 5 tions alter the current view that, few percent of our genome, a logical genes, it is easy to see how a rela- genetically, humans are not espe- guess is that human-specific muta- tively small number of mutations in cially unique as a species. tions are clustered in our genes. regulatory sequences could alter the Interestingly, this is not the case. A function of an entire network of genes third of our proteins are perfectly and thereby influence a trait, such as pelvic morphology or brain size. identical to the chimp version, and REFERENCES the rate of DNA differences in genes But individual mutated bases of is about half of the genome average. DNA are not the whole story. During 1 The Chimpanzee Sequencing and Analysis evolution, stretches of DNA can be Consortium. 2005. Initial sequence of the There are genes, especially in the chimpanzee genome and comparison with the immune, digestive, and reproductive copied, deleted, or rearranged in a human genome. Nature 437:69–87. systems, with mutations that likely species’ genome. These structural 2 Rat Genome Sequencing Project Consortium. variations can lead to destruction or 2004. Genome sequence of the Brown Norway change in the functions of the genes rat yields insights into mammalian evolution. Nature 428:493–521. Katherine Pollard is at the Gladstone and regulatory sequences they con- Institutes, Institute for Human Genetics, 3 King MC, Wilson AC. 1975. Evolution at two and Division of at the tain. The consequences are often det- levels in humans and . Science University of California San Francisco. rimental, but occasionally beneficial. 188:107–116. Dr. Pollard’s lab develops statistical and For example, the loss of olfactory 4 Prud’homme BP, Gompel N, Carroll SB. computational methods for the analysis 2007. Emerging principles of regulatory of genomic datasets. Her research receptors in humans has been linked evolution. Proc Natl Acad Sci USA 104:8605– focuses on genome evolution, particu- to adaptive changes in our sense of 8612. larly on identifying DNA sequences that smell and bitter taste perception, 5 Pollard KS, Salama SR, King B, et al. 2006. differ significantly between or within spe- Forces shaping the fastest evolving regions in cies and their relationship to biomedical suggesting that humans are in some the human genome. PLoS Genet 2(10):e168. traits. Many of these sequences encode ways degenerate apes. Uniquely regulatory signals, structural sites, and 6 Cain CE, Blekhman R, Marioni JC, et al. RNA genes. human structural variations com- 2011. Gene expression differences among pri- Email: [email protected] mates are associated with changes in a histone prise several times more bases of our epigenetic modification. Genetics 187:1225– genome than do human-specific sin- 1234. ISSUES 185 Why We Are Not Chimpanzees?

ROBERT SUSSMAN

What makes us human? We all The totipotentiality of behaviors for The differences between chimpan- would agree that chimpanzees differ each species differs. Although there zee populations across Africa are from gorillas, both in their anatomy might be some overlap in the behav- trivial compared to the differences and their behavior. They have differ- iors of chimpanzees and humans, between human populations, and ent behavioral repertoires, different the total potential of their behavioral these differences can be quantita- ethograms. Just as chimpanzees dif- repertoire is different. They have dif- tively compared. For example, chim- fer in their nature from gorillas, so ferent natures. panzee systems are essen- too do they differ from humans. In Can we operationalize these tially the same in all populations, this light, humans have different differences? Can we measure the dif- whereas those of humans vary tre- natures from both chimpanzees and ferent behavioral repertoires of dif- mendously. In chimpanzees, kinship gorillas. Each of these ‘‘higher prima- ferent species? Can we describe and directly relates to familiarity, prox- tes’’ has a unique nature. compare their different potentials? imity, and direct day-to-day, rela- In attempting to describe what Each population of a species should tively short-term interactions. makes us human, it is necessary to have the potential to perform the Human kinship is a created symbolic compare humans with nonhuman total repertoire of the species, but system not restrained by time or primates. Some comparisons of this the distribution of behaviors of any place, living or dead, or necessarily sort are quite simple. Chimpanzees population might display only a sta- by any biological relationships, and are knuckle-walkers, humans are tistical representation of the total is extremely variable across Africa. It bipedal; chimpanzees instinctively repertoire. We should be able to is the product of symbolism, lan- build nests, humans do not; chimpan- compare the behavioral totipotential- guage, and , the things that zees are adept at locomoting in trees, ity of different species and compare make us human. humans are not. Other aspects of the repertoire of different popula- How would we study the totipo- human and chimpanzee natures tions within the same species. We tentiality of human nature? By relate to differences in how the brain must be careful in making our using , archaeology, his- functions. These differences are more comparative ethograms, however, tory, and , we can try to difficult to compare. because similar behaviors might be outline the totipotentiality of human We don’t understand how differen- different, depending on context, his- behavior through time and among ces in the brains of chimpanzees and tory, and such. living human . All of these humans relate to complex behavioral Back to the question of what makes things are part of human nature; differences. However, we do know us human: we can compare the be- they are biologically and genetically there are profound behavioral differ- havioral totipotentiality of humans possible. To say, for example, that ences; the structure and function of and chimpanzees. I believe there are humans are by nature aggressive is their brains differ. Each is unique, three human behavioral traits not true but trivial; they are also by and this leads to unique behaviors. found in chimps or any other animal; nature cooperative. We need to Chimpanzees and humans are they are unique and exemplify what it compare the distributions of behav- ‘‘playing different games.’’ Say, chim- means to be human: symbolic behav- iors within and between each culture panzees are playing checkers and ior, language, and culture. Symbolic or subculture, then to quantify and humans are playing chess. Each has behavior is the ability to create alter- compare the distribution of behav- a different behavioral repertoire, a native worlds, to ponder about the iors. For example, we might find different set of rules. Given the rules past and future, to imagine things that homicide occurs in all cultures. of the game within which each spe- that don’t exist. Language is the However, we might also find that cies can operate, it can only make unique communicative venue that the norm, statistically, is that the certain moves, perform certain enables humans to communicate not homicide rate is always exceedingly behaviors; it has a unique ethogram. only in proximate contexts, but also low as compared to the rate of about the past, the future, and things cooperative or altruistic behaviors. distant and imagined, allowing us to We would also find that homicide Robert W. Sussman is Professor of An- share and pass our symbols to future rates vary between and among cul- thropology at Washington University in St. Louis. His recent books include Man generations. Culture is the ability tures. Is this variation genetic or the Hunted (with Donna Hart) and Origins found only in humans for different culturally determined? Homicidal of Altruism and Cooperation (edited with C. Robert Cloninger). He is past Editor of populations to create their own behavior is part of human nature, American and the Year- shared symbolic worlds and pass but this is not useful in explaining book of Physical Anthropology, and them on. Although chimpanzees can homicide rates, which are culturally Secretary of the Anthropology Section, A.A.A.S. pass on learned behavior, they cannot determined. Culture is the unique Email: [email protected] pass on shared and different world part of human nature; homicide is views. not. 186 ISSUES Cognition, Communication, and Language

ROBERT M. SEYFARTH AND DOROTHY L. CHENEY

Although fully evolved language motivated to share them with others. of phonation, which are largely provides the most striking difference The lack of these traits — the lack of innate and physiologically complex, between modern human and nonhu- a fully developed ‘‘theory of mind’’ whereas comprehension depends on man primates, in the domain of com- and the motivation to share informa- mechanisms of learning, including munication and cognition, two sim- tion with others — distinguishes classical and operant conditioning, pler, more basic features, both neces- nonhuman primates from humans. which are considerably more mallea- sary precursors of language, are But there is another, even more ba- ble and widespread even among ani- what make humans unique. Nonhu- sic difference in communication that mals with very different brains. But man primates have sophisticated sets monkeys and apes apart from this explanation offers no answer to perceptual systems almost identical us. In monkeys and apes, vocal pro- two crucial questions: why has natu- to ours, but only a limited ability to duction is highly constrained. Com- ral selection so rarely acted to favor represent one feature of their envi- pared with humans, but like most flexible vocal production in mam- ronment that they cannot see: the other mammals, nonhuman primates mals and what were the circumstan- mental states of another. This skill is have a relatively small repertoire of ces that made humans an exception? not completely absent: like very calls, each of which is used in a re- One speculation argues that the young children, monkeys and apes stricted set of social contexts. The selective pressures imposed by an can recognize another individual’s acoustic features of calls are largely increasingly complex social environ- motives and, as a result, anticipate genetically fixed, with only limited ment favored the evolution of a full- what that individual is likely to do modification during development. blown theory of mind, and this, in 1,2 next. They can also engage in sim- Differences from human speech — turn, favored the evolution of ple forms of shared attention and acoustically flexible, learned, and increasingly complex communication 3 social referencing. However, mon- highly modifiable — are obvious.4,5 that required flexible vocal produc- 6 keys and apes appear unable to rec- Monkeys and apes overcome some tion. Whatever the outcome of such ognize what another individual of these limitations with a rich sense speculation, in the domains of cogni- knows. They also cannot perceive of what linguists call pragmatics: tion and communication, two fea- when another individual holds a they have an almost open-ended abil- tures, more than any other, make us false belief. ity to learn sound-meaning pairs, uniquely human: a limited theory of Monkeys’ and apes’ knowledge of recognize individual voices, and mind and inflexible vocal production. their own thoughts is similarly lim- combine information about individu- ited. They seem incapable of the sort als’ social positions, past interac- of ‘‘what if’’ introspection that allows tions, and current motives when REFERENCES deliberate planning and the weighing assessing the meaning of vocaliza- of alternative strategies. In contrast, 1 Cheney DL, Seyfarth RM. 2007. Baboon tions. In their interpretation of the metaphysics. Chicago: University of Chicago one-year-old children are not only meaning of vocalizations, listeners Press. aware of their thoughts but highly combine discrete-valued entities in a 2 Cheney DL, Seyfarth RM. 2012. The evolution of a cooperative social mind. In: Vonk J, Shack- structured, rule-governed, and open- elford T, editors. Oxford handbook of compara- ended manner.6 Their discrete, com- tive . Oxford: Oxford Robert Seyfarth and Dorothy Cheney University Press. pp. 507–528. are, respectively, Professor of Biology positional perception has interesting 3 Tomasello M, Carpenter M. 2007. Shared and Psychology at the University of parallels with language; their re- Pennsylvania. For 11 years, they con- intentionality. Dev Sci 10:121–125. ducted field research on the social stricted production has none. 4 Hammerschmidt K, Fischer J. 2008. behavior and communication of vervet The striking difference between Constraints in primate vocal production. In: monkeys in Kenya, resulting in the publi- Griebel U, Oller K, editors. The evolution of cation of How Monkeys See the World production and comprehension is communicative creativity: from fixed signals to (1990, University of Chicago Press). puzzling because producers are also contextual flexibility. Cambridge: MIT Press. Between 1992 and 2008, they directed a perceivers: why should an individual pp. 93–119. field study of social behavior, communica- that can deduce an almost limitless 5 Seyfarth RM, Cheney DL. 2010. Production, tion, and cognition among baboons in the usage, and comprehension in animal vocaliza- Okavango Delta of Botswana, resulting in number of meanings from the calls tions. Brain Lang 115:92–100. the publication of Baboon Metaphysics of others be able to produce only a Seyfarth RM, Cheney DL. 2012. Primate (2007, University of Chicago Press). 6 social cognition as a precursor to language. In: Email: [email protected], limited number of calls of its own? Gibson K, Tallerman M, editors. Oxford hand- [email protected] The difference may arise because call book of language evolution. Oxford: Oxford production depends on mechanisms University Press. pp. 59–70. ISSUES 187 A Neuroanthropological Perspective

BENJAMIN CAMPBELL

What makes us human? I argue it to be intertwined with social intelli- Craig1 refers to such an awareness is a brain that has evolved under gence. In fact, the large size of the as the salient self, a term implying social pressure to make us self-aware human brain is primarily a function individual self-awareness. However, individuals who define ourselves by of increased cortical area. Most of other findings indicate that in addi- what we share with a group of famil- the cortex serves as association tion to integrating sensations from iar others. While that group of famil- areas, integrating sensory inputs into within the body, the insula integrates iar others originally extended no far- larger and larger bits of information external social signals as well, ther than a band or tribe, it has since that can be used by the prefrontal including sound and touch. In the grown until it now includes, to vary- cortex for decision-making. Hence rhesus , neurons within the ing degrees, a global human popula- the size of the human cortex means insula respond to species-specific tion. And with that, the focus on that many different features of other calls, but not other sounds.2 Simi- what makes us human has shifted individuals and the environment can larly, in humans, the insula responds from being a member of one group be used to discriminate social situa- to music and language, both learned as opposed to another to being a tions and help us to choose a practices that are often used to member of the same species as dis- response, allowing the complex define group membership. These tinct from other species. social strategies with which we are findings imply that the salient self is Humans are distinct from our clos- familiar as humans. not simply an individual experience, est relatives, the great apes, in hav- Compared to social cognition, but includes a larger learned social ing an extended life span, late matu- potential changes in social emotion dimension. In other words, the sense ration, and higher reproductive rates. over the course of human evolution of being okay is experienced as the At the center of these traits lies the have received much less attention. state of both one’s body and the human brain, roughly six times Recent findings indicating that the larger social group. larger than expected based on body human amygdala, associated with Recent brain imaging studies have size and three times larger than the emotional saliency, is larger than that shown the insula is activated in the chimpanzee’s. It is our large brains of other hominoids, suggest possible case of social exclusion, as well as that take a long time to develop. At species differences in emotion. social inequality. It appears that our the same time, our brains allow us Humans may be more, rather than brain anticipates group membership not only to be more economically less, emotionally sensitive to their based on equality as the default con- productive as adults and capable of social environment, giving the group a dition, and when this expectation is subsidizing, as a group, the energy greater impact on our emotional life. violated the insula senses a threat to demands of our slow-developing off- In this context, the insula, a small bodily well-being. Such a picture is spring, but to still reproduce at a cortical region between the temporal entirely compatible with our evolu- higher rate than do any of the extant and frontal lobes, is of particular in- tionary history as hunter-gatherers hominoids. In other words, the selec- terest because of its role in integrat- dependent on each other for survival. tive pressures that led to a larger ing emotion and bodily sensation. In sum, humans are inherently brain centered on group interactions Via the thalamus, the posterior group beings with shared practices that continue throughout the life insula receives afferents through a and beliefs, a point that social span. network of unmyelinated fibers from anthropologists have insisted on for It follows that species-specific fea- different parts of the body, including some time. Such a definition can tures of the human brain are likely muscles, gut, and skin. These sensa- only be deepened by pointing to the tions, continually updated, are inte- way in which shared practices and beliefs are generated by our brains Benjamin Campbell is Associate Profes- grated within the posterior insula to sor of Anthropology at University of create an ongoing representation of as a consequence of our evolutionary Wisconsin-Milwaukee. His recent re- the body. This information is relayed past. search focuses on . His article ‘‘Male Embodiment and Vital- to the anterior insula, where it is ity in Subsistence ’’ will appear integrated with emotional impulses in Neuroanthropology, edited by Greg REFERENCES Downey and Daniel Lende (MIT Press) from the amygdala to create an this fall. He is also the co-editor (with ongoing global emotional aware- 1 Craig AD. 2010. The sentient self. Brain Michael Crawford) of Causes and Conse- ness of bodily homeostasis; that is, Struct Funct 214: 563–577. quences of Human Migration (Cambridge University Press) due out this fall. whether, right now, as a whole, 2 Remedios R, Logothetis NK, Kayser C. 2009. Email: [email protected] An auditory region in the primate insular cortex things are within tolerable limits or responding preferentially to vocal communica- not. tion sounds. J Neurosci 29:1034–1045. 188 ISSUES Comes the Child Before Man: Development’s Role in Producing Selectable Variation

SARAH HRDY

A concatenation of events and adapta- aptitudes make cooperation toward impulses in a great ape avoids the need tions led a line of bipedal, already clever, shared goals possible. to invoke unique evolutionary processes tool-crafting apes in the genus Homo to Since Darwin, explanations for or activities that may or may not have evolve even larger brains with special humankind’s peculiarly other-regarding been relevant for widely dispersed for- aptitudes for language and for transmit- tendencies have focused on the need for agers in Plio-Pleistocene Africa. Allopar- ting elaborate information, including ‘‘altruistic’’ cooperators to collaborate in ental provisioning has evolved multiple templates for socially approved (‘‘moral’’) hunting or lethal intergroup warfare. times in multiple taxa as kinship or behavior. It is unlikely that such apes But if advantages from hunting or raid- mutualistic benefits induced alloparents could have evolved had they not already ing were sufficient, why didn’t the pred- to bring back food for someone else’s been peculiarly ‘‘other-regarding.’’ It is atory or raiding ancestors of chimpan- dependent young to a hive, den, or the emergence of this facet of human zees (with six million years at their dis- home base. As in most primates, ances- nature that intrigues me most. posal) evolve to be more cooperative as tors of early hominins would have been Other apes can attribute mental well? Why is coordinated helpfulness so susceptible to signals of need from altri- states to someone else, as when subor- rare? cial young, as well as buffeted by unpre- dinates recognize what a dominant can Elsewhere in nature, communal nur- dictable rainfall and resources, condi- and cannot see. They have the requisite ture of young has been a precursor to tions known to predispose vertebrates neurological equipment for newborns higher forms of cooperation. Rudimen- to evolve cooperative breeding. to imitate some facial expressions in a tary forms of shared infant care are I propose that cooperative breeding caretaker, as human newborns do. found across the primate order, albeit had begun co-evolving with slower mat- Under some circumstances, chimpan- not among great apes, where highly pos- uration and larger brain sizes by 1.8 mil- zees identify another’s plight or need sessive mothers restrict access. Yet lion years ago. For this model to work, and help, sometimes in targeted ways. bipedal apes in the climatically unpre- both sexes, albeit at various life stages, Bonobos and chimpanzees may share dictable savanna-woodlands habitats of had to be able to move between groups, food with one another, albeit typically Plio-Pleistocene Africa, burdened by the gravitating away from adversity and to- grudgingly or only after persistent costliest young in mammaldom, could ward opportunities where resources at solicitations. Profoundly self-serving, have ill afforded exclusive mothering. issue included not only food, water, or they rarely, if ever, spontaneously Alloparentsaswellasfathersmusthave mates, but opportunities to receive or share and cooperate with others the helped care for and provision young (the strategically provide allomaternal assis- way humans routinely do. Yet from an ‘‘Cooperative Breeding Hypothesis’’). tance to kin. Although multi-local resi- early age, human infants voluntarily Demographic, life-historical, and dence patterns are well documented in proffer food to someone else, even biogeographic implications of such the ethnographic record, it is not yet selecting precisely the item a recipient unapelike child-rearing are becoming known how far back in time such porous is most likely to enjoy. Long before they increasingly well understood. But there social boundaries go. Nevertheless, can speak, human infants obsessively would also have been psychological extrapolating from what developmental monitor intentions and are eager to corollaries. These include mothers who psychologists are learning about modern learn what someone else thinks and are acutely sensitive to cues of alloma- humans and collateral ape lines, if early feels, including what someone else ternal support with levels of maternal hominins relied on multiple caregivers, other-regarding impulses and more inte- thinks and feels about them, leading commitment contingent on them; vari- grated perspective-taking would logically babies to express symptoms of pride or able levels of male commitment sensi- follow. If so, long before the evolution of shame. When combined with impulses tive not only to probabilities of pater- behaviorally modern humans capable of to share and help, these other-regarding nity and mating options, but also to symbolic thought and language, and alternative sources of nurture; and off- even before anatomically modern big- spring developing in social contexts Sarah Hrdy is an old-fashioned anthropol- brained humans, emotionally modern where they needed chronically to moni- ogist whose most recent book, Mothers hominins that already were psychologi- and Others: The Evolutionary Origins of tor and respond to the mental states cally different from other apes would Mutual Understanding, was awarded the and intentions of others, resulting in a have been questing for intersubjective 2012 J. I. Staley Prize for outstanding cognitively and emotionally different scholarship and writing that crosses sub- engagement. disciplinary boundaries ‘‘to add new developmental outcome. Over genera- dimensions to our understanding of the tions, these novel ape phenotypes human species,’’ which is exactly what would have been subjected to quite she and this project are trying to do. She ACKNOWLEDGMENTS is Professor Emerita in the Department of novel social selection pressures, so that Anthropology at the University of Califor- youngsters just a little better at moni- I rely on work by K. Bard, J. nia, Davis, associate of the Peabody Mu- toring the mental states of others, at Burkart, K. Hawkes, B. Hewlett, F. seum of Archaeology and , appealing to and soliciting nurture Marlowe, T. Matsuzawa, M. Tomasello, Cambridge, Massachusetts, and A. D. White Professor At Large at Cornell from them, would be the best cared C. van Schaik, M. J. West-Eberhard, and University, Ithaca, New York. for, best fed, and most likely to survive. P. Wiessner. For references, see Mothers Email: [email protected] This explanation for the initial and Others: The Evolutionary Origins of emergence of more other-regarding Mutual Understanding. ISSUES 189 Grandmothers and Their Consequences

KRISTEN HAWKES

Both what we share and don’t declining fertility. This novel oppor- at birth are not measures of longev- share with our primate cousins make tunity is central to the Grandmother ity. Instead they are very sensitive to us human. Easy enough to start a Hypothesis: by provisioning grand- the short lives of dying babies and list. At least since Darwin, most children, elders would allow younger rise dramatically when infant and would rate moral sentiments as dis- females to bear subsequent babies juvenile mortality decline. tinctively human. But our modern sooner without net losses in off- Sarah Hrdy revealed a momentous selves didn’t emerge from ancestral spring survival. As more vigorous implication of our grandmothering apes in one step. When did popula- grandmothers left more descendants, life history in developing her Cooper- tions along the way become human? rates of aging slowed. That raised ative Breeding Hypothesis. Hrdy Before our big modern brains, before longevity and the fraction of female does not privilege grandmothers as I language, and before pair bonds, our years lived past the fertile ages. The do here, but her synthesis identifies longer lives, later maturity, and ear- reduction in adult mortality lowered far-reaching consequences of human lier weaning could have evolved in the risk of dying before reproducing, mothers’ reliance on others for suc- an already smart and gregarious favoring delayed maturity to net the cessful childrearing. Great ape moth- ancestor due to rearing help from benefits of further growth to larger ers focus on one infant at a time. grandmothers. Although cooperative adult size. But human mothers have overlap- hunting and lethal between-group Our characteristic postmenopausal ping dependents to juggle and must aggression are often nominated as longevity has long been recognized worry about the availability and dis- evolutionary foundations for human as a major clue to the evolution of position of helpers. As a result, prosociality, neither distinguishes us human life history. But when George human babies, unlike other ape from chimpanzees. Grandmothering Williams tackled it more than half a infants, cannot count on their moth- does. Our grandmothering life his- century ago, menopause was still er’s full attention. Both mothers and tory intensified selection on infant thought to be uniquely human. He grandmothers have investment alter- appetites and capacities for social proposed that it evolved because natives; in high-mortality environ- engagement, the foundation of our other changes in our lineage made ments, their commitment can mean moral faculties. late births riskier and offspring more life or death. So grandmothering What could have led to these dependent. Subsequent evidence makes infant survival more subject changes in hominin life history? shows that women don’t stop early. to variation in infants’ own abilities Plio-Pleistocene climates posed great Female fertility ends at similar ages to engage caregivers. Human infants’ challenges as increased aridity and in humans and the other great apes. sensitivity to that engagement leaves seasonality constricted the distribu- The human difference is not meno- them (ironically?) more psychologi- tion of foods that ancestral ape pause, but our slower somatic aging. cally vulnerable to social approval. youngsters could effectively handle. Other apes become frail during the The increased stakes for infants in- That left mothers two choices: follow fertile years and rarely outlive them. tensify the sociality that we share the retreating foods and maintain Not so humans. Among traditional with other primates. Social bonds the diets their weanlings could man- hunter-gatherers, a girl lucky enough matter across the order, as demon- age or subsidize them longer. to survive childhood usually has strated by long-term demographic Increased juvenile dependence would more than a 70% chance of living and behavioral observations, experi- allow mothers to remain in habitats beyond the childbearing years; and ments, and hormonal assays, both in inhospitable to youngsters and move women are more economically the wild and captivity. Starting from into new ones as well. Although productive after menopause than ancestral ape sociality, grandmother- extended juvenile neediness would before it. ing magnifies selection pressures for seem to reduce a mother’s reproduc- In these hunter-gatherer popula- desires and capacities to engage mu- tive success, it offered a novel fitness tions, the standing fraction of adult tual attention in earliest life. So the opportunity for older females with women beyond the childbearing ages social virtues Darwin identified as is near a third, even though life distinctively human need not depend Kristen Hawkes is Distinguished Profes- on the bigger brains and language sor of Anthropology at the University of expectancies at birth are less than 40 Utah. Her studies of hunter-gatherer years. Life expectancies in that range that certainly distinguish us. Instead, foraging strategies aim at improving contribute to another common mis- our brains, language, and even pair hypotheses about human evolution. The importance of grandmothers’ help provi- take. The fact that the highest bonds may depend on the prior evo- sioning youngsters drew her attention national life expectancy now almost lution of strong appetites for shared to the evolution of human longevity, doubles the global record of 1850 is intentions, with sensitivity to praise prompting her continuing comparisons of human and chimpanzee aging. widely cited as evidence that post- and blame selected in ancestral Email: [email protected] menopausal survival is an artifact of youngsters reared in environments recent history. But life expectancies with ancestral grandmothering. 190 ISSUES How We Give Birth Contributes to the Rich Social Fabric that Underlies Human

KAREN R. ROSENBERG

In comparing humans with other alization that evolved in mosaic fash- nant, birthing, and nursing mothers primates, one should emphasize the ion over the last 6-4 million years, and may be a critical aspect of our adap- continuities as much as the distinc- the resulting position in which babies tation. It allows female members of tions. It may be futile to seek a single, emerge, facing away from their our species to gestate large-bodied critical, and universal human charac- mother. As a result, laboring women offspring, birth those large-brained, teristic to explain the essence of our benefit from the presence of a birth at- broad-shouldered babies, and care uniqueness. Nevertheless, considering tendant who increases the survival for and carry those large, helpless those factors in which we are distinct chances for both mother and infant newborns outside the womb for elucidates significant aspects of human by such acts as receiving the emerging extended periods. Montagu charac- . Arguments can be made baby, moving an umbilical cord from terized human fetuses as ‘‘extero- for morphological , like around a baby’s neck or clearing its gestate,’’ meaning that they continue bipedalism or encephalization, or cul- breathing passage, encouraging a to grow outside the womb at rapid tural behaviors, like language, tool use, mother to change positions to create a fetal rates only because of our cul- , or art, that are unique to more spacious birth outlet or to allevi- tural ability to buffer helpless new- humans or more elaborated than in ate shoulder dystocia (a birth obstruc- borns from environmental stresses. other primates. Hrdy and other tion that can result in injury such as Human babies have also evolved to authors argue that humans are ‘‘coop- paralysis of the infant’s arm), or pro- demand this care, resulting in what 1:433 erative breeders,’’ meaning that parents viding emotional support during a Wolpoff described as ‘‘the combi- share the child-rearing efforts with long, exhausting labor. Clinical nation of physical altriciality and other individuals in their social groups. research on doulas (birth attendants social precociality in which children These alloparents may be grandpar- who provide emotional support to who cannot jump off the ground ents, older siblings, other close rela- the mother rather than assist directly with both feet can control and tives, or nonrelatives, and have impor- in the mechanics of birth) shows manipulate every adult they come in tant implications for our social and that attention to women’s emotional contact with,’’ maximizing the adult emotional dynamics. Alloparental care and social needs during labor leads attention they receive. is important during the long phase of to shorter labors and fewer complica- Beyond birth assistance, invest- juvenile development that humans tions. In contrast to birth among other ment in infancy is also possible begin as helpless but large-bodied primates, which is generally solitary, because humans help each other by infants. I focus here on two aspects of human rotational birth may not sharing the high energy demands, in- cooperation that are direct consequen- have been able to evolve outside a tensive monitoring, and attentive ces of the human birth pattern: assis- social context in which women care that benefit mothers and their tance during labor (and, more gener- had physical as well as emotional babies so much. The relationships ally, support of mothers during preg- assistance during birth. Rotational women form with one another as a nancy, childbirth, and lactation) and birth probably evolved in the early- result of this sharing of effort create care of helpless newborns. middle Pleistocene and may have intense emotional bonds that form A striking example of reproductive made possible dramatic encephaliza- one underpinning of the uniquely cooperation is what Trevathan called tion in humans, making birth assis- complex extended and non- ‘‘obligate midwifery’’ or birth assis- family social networks universal to tance a longstanding part of human tance. Human birth is complicated in humans. This web of social ties, and adaptation. that infants rotate as they pass its elaboration in support of human Beyond this important direct help through the birth canal, a result of reproduction and child rearing, are during childbirth that is so charac- pelvic adaptations to the conflicting among the critical factors that teristic of humans, we support preg- constraints of bipedalism and enceph- shape the unique human adaptation nant or lactating women. Piperata and, despite our close genetic and showed that during the postpartum behavioral ties to other primates, es- period, when energetic demands are tablish a pattern of social behavior Karen R. Rosenberg is Professor and high, women receive help in the form that sets us apart from our primate Chair of Anthropology at the University of of social support from members of Delaware. She is a biological anthropolo- relatives. gist with interests in paleoanthropo- the community and often do not con- logy, specifically in the origin of modern tinue their normal work. Assistance humans, with particular focus on East Asia also takes the form of sharing work and the evolution of the modern pattern of human childbirth and infant helplessness. and providing food or child care. REFERENCES Email: [email protected] Intensification of effort in support 1 Wolpoff M. 1999. Paleoanthropology. Second of the reproductive success of preg- edition. Boston: McGraw-Hill. ISSUES 191 To Whom Does Culture Belong?

MARY C. STINER AND STEVEN L. KUHN

For millennia, scholars have lating the modern human species cat- iors are transmitted by means other viewed humans as members of the egorically from all other animals, than human language. Yet humans animal kingdom, sharing many char- present and past, is common to many share culture through both linguistic acteristics with creatures as diverse narratives of human evolution as well and nonlinguistic modes of communi- as horseshoe crabs and bats. For at as religious accounts of human crea- cation. Body language, gesture, and least as long, people have sought to tion. As intuitively appealing as this simple performance are central to the identify the features that distinguish practice may be, claims of absolute transmission of many skills and physi- us humans from other organisms, breaks with other life forms are cally embodied forms of cultural features that make us utterly unique. impediments to learning how humans knowledge, such as dance and many Complex ‘‘culture’’ and a linguistic developed their remarkable facility crafts. Why should we admit these as mode of communication are two of for and dependence on culture. channels for cultural transmission in the most obvious things that make At a genetic level, it is easy to see humans but disallow them for other humans human. Culture is about that a great deal of what makes us social organisms? knowledge building, conservation, human is what also makes us mam- Virtually all scholars will agree that and transfer. Its most remarkable mals, vertebrates, or multicellular culture redefined the character of the property is that it can be shared organisms. Nowhere is this more evolutionary process in humans, among individuals and across genera- apparent than in our DNA, with more allowing us to leap across adaptive tions independently of genetic inheri- than 98% shared with chimpanzees thresholds quickly and efficiently. tance. While humans are uniquely and only somewhat less shared with This viewpoint leaves two distinct cultured, they may not be the only chickens and mice. Any number of re- questions for the next generation of creature that possesses a capacity for markable developments in how animal social . Just how unique is culture. In fact, there is considerable species interact with the physical the capacity for culture among intel- diversity of opinion among anthropol- world have resulted in whole new ligent species, of which humans are ogists as to whether culture as a cog- dimensions of existence. Several of but one? And how specialized are the nitive and behavioral adaptation dis- these have evolved more than once in various means for sharing elements tinguishes humans from other ani- the history of life. Flight is one exam- of learned traditions with conspe- mals absolutely or only by degree. ple that continues to instill wonder cifics? All modes of communication The question of whether we are and confound evolutionary scientists. are tools for information transmis- alone in our possession of culture is We know that the capacity for flight sion; there must be a point where also fundamental to understanding developed independently in birds and imitation grades into ritualized ges- how this most typical of human char- bats, both of which rely on modified ture and ritualized gesture into re- acteristics came into being. To study forelimbs, while invertebrate insects combinable structured elements. evolutionary processes of any sort, we took to the air using entirely different Modern human language is extraor- must identify where and how certain structures. Knowing this fails, how- dinarily versatile, and there is noth- traits derived from earlier, simpler ever, to tell us how wings came into ing quite like it to be found in other forms, and how they were amplified, being in general or in each case. animals. That experiments with non- altered or eliminated with time. Iso- Today, we commonly appeal to prea- human primates or cetaceans fail to daptations for flight that arose by elicit human language is hardly the chance, were favored by more proxi- point, however. Apes and dolphins Mary C. Stiner is Professor of Archaeol- ogy in the School of Anthropology at mate needs, and happened to potenti- should not be expected to emulate the University of Arizona in Tucson, AZ. ate rapid movement of a new kind. our modes of communication any She conducts archaeological research on Paleolithic and early Neolithic sites And then we try to find out what those more than dragonflies should be across the Mediterranean region. Her characteristics would have been. expected to fly like birds. interests include human evolution and Cultural transmission of informa- A central aim of anthropology is to paleoecology, ancient hunting practices, animal domestication, and early orna- tion and behavioral traditions is understand the origins of humans mental traditions. another remarkable development in and the complex behaviors that char- Email: [email protected] the evolution of life. Should it be con- acterize us today. If this is our goal, Steven L. Kuhn is Professor of Archaeol- ogy in the School of Anthropology at sidered the singular possession of the question of what species may the University of Arizona. He explores humans? Behavioral studies show that possess something akin to culture changes in ecology, foraging adapta- tions, and land use of Pleistocene homi- other social mammals and birds de- must be more inclusive. Otherwise, nins through Paleolithic technologies. He velop local knowledge traditions that we run the risk of shutting the door has conducted field and laboratory stud- are passed among individuals and to understanding how humans ‘‘got’’ ies in Italy, Israel, Turkey, Greece, Syria, Serbia, and the U.S. across generations. It seems that the culture in the first place, ignoring Email: [email protected] main barrier to calling these examples the evolutionary substrate of our rudimentary culture is that the behav- own unique cognitive evolution. 192 ISSUES To Be or Not To Be (Human), Is that a Question?

KEN WEISS

What makes us human? This sequence. Evan if from just a single tions of many different genes, each seems a perfectly reasonable, inter- person, any two instances, between varying. Hence each instance of the esting question to ask but, even on people or within any person, differ trait is genetically different! superficial examination, it’s really from the reference by a few million This complexity suggests that we not meaningful at all. By the usual nucleotides. So do we need a second, should turn to traits rather than criterion that a scientific statement out-group reference such as ‘‘the genes. Would they be tooth morphol- must be testable, it is not clear that chimpanzee’’ sequence (itself just a ogy, pelvic shape, or the position of answers to ‘‘What makes us human?’’ type-specimen) to give us an outer the foramen magnum? Perhaps we’d would qualify. Or is this a humanis- bound of humanness? prefer the traditional favorites of our tic rather than scientific question? Even in the simplest comparisons, hubris, language and intelligence. Is Think of it this way: Look in a mir- a random human and chimp there a qualifying IQ or elocution ror; what do you see? How do you sequence differ by tens of millions of cutoff we can use? We might just as know it’s ‘‘human’’? Let’s consider nucleotides. But there is also substan- well pick, say, armed warfare or reli- what a scientifically meaningful an- tial identity, varying in detail with gion as ‘‘making us human,’’ except swer might entail. each comparison one might use; that that would disqualify Quakers and We couldn’t simply agree to count won’t help define what’s uniquely atheists. Trait selection provides no anyone as human who is born to human, so it’s not a terribly satisfying easy answer. qualified ‘‘human’’ parents. That just solution. And why pick on chimps? Clearly, humans are something dif- bumps the question back a genera- Why not, say, gorillas, giraffes, or ferent from anything else, and yet, tion, and another generation, and growling Neandertals, since we have individually, no one of us is identical another, until at some point in fossil- (a Platonic composite of) their to anyone else. Indeed, our under- ized history we’d have gone back sequences. Or were they also standing of evolution depends on enough generations to question ‘‘human’’ and hence no out-group? population thinking, and the answer whether the parents still qualified as Clearly, something relevant to the to what makes us human is necessar- human. So that doesn’t work. question involves genes, but it is not ily a collective one. However, that is One obvious, seemingly objective so clear just what it is. Perhaps we ephemeral and less than crystal answer that quickly comes to mind should choose ‘‘the’’ gene for some clear, because every instant the col- is possession of ‘‘the human ge- chosen trait (another Platonic ideal)? lection changes with new individuals nome.’’ However, I put that in quotes Who decides which gene? When one (and unique genotypes) being born because there is no such thing! It’s a nucleotide can be the difference and others lost. Platonic ideal, a DNA sequence between life and death by disease or If a rhesus looks in a mirror, what assembled from perhaps more (the failed embryological development, does it see? Does it make its own truth is currently unclear) than one which should count? Surely we species distinction? If only it could person, that’s repeatedly updated should include individuals who are tell us how. Let’s parse the question and corrected. It’s not even as intui- not the Platonic ideal of human, per- itself: ‘‘What’’ implies enumerable tively obvious as a traditional type- haps lacking some typical trait, such components, ‘‘makes’’ implies deter- specimen because, as a composite, as vision, hearing, limbs, or ‘‘normal’’ minative causation, and ‘‘us’’ implies no human (whatever that means!) intelligence. But where is the line to collective identity. Finally, ‘‘human’’ ever had that sequence. It is strictly be drawn? vaguely implies that we know the an arbitrarily agreed-on reference Genome sequence analysis shows answer ahead of time, to which the that each human (assuming we know other words relate, an inherently in advance what that means!) carries circular definition. So overall, this Ken Weiss is Evan Pugh Professor of a unique set of numerous genes that, really isn’t much of a scientific ques- Anthropology and Genetics at Penn because of mutation, are not func- tion, after all. State University. His interests are in tional, but that would otherwise In the end, we can rest easy, how- genetic variation and causal complexity, and the evolutionary processes that gen- seem to be necessary because, for ever. Every answer to the question of erate them. His research on these topics example, if you inactivate it in a what makes us human is elusive. involves simulation, genome mouse, the mouse turns belly up. Everyone will understand the ques- mapping, and experimental developmen- tal genetics of craniofacial variation. Other genes probably cover the inac- tion differently and can answer it Email: [email protected] tivated genes’ functions. Indeed, without fear of contradiction. That, most traits are due to the interac- after all, is what makes us human! ISSUES 193 Reprise: What Does Make Us Human?

JAMES M. CALCAGNO AND AGUSTI´N FUENTES

As expected, ten different essays supports our original expectation of als.’’ He points to find- provided ten distinctive responses different perspectives emanating not ings that our ‘‘sense of being okay is to the question, ‘‘What Makes Us only from major research specialties, experienced as the state of both one’s Human?’’ Thus, it is not surprising but also within them, given Dr. Pol- body and the larger social group.’’ that undergraduate students, when lard’s genetic viewpoint. Although Similarly, Drs. Hrdy, Hawkes, and faced with the same question at the Pollard clearly recognizes that ‘‘not Rosenberg focus on social interac- start of an introductory course in bi- very much’’ separates us from the tion and cooperation in their essays, ological anthropology, have difficulty chimpanzee genome, she also points each offering insight into what answering it at the end of the semes- out ‘‘that a few key changes in the ‘‘made’’ us human. Hrdy emphasizes ter. Our ambitious (perhaps unrealis- right DNA sequences had big alloparental care more generally to tic) goal here is to provide a coherent effects...all of which distinguish explain why ‘‘humankind’s peculiarly response that is comprehensive humans as a species.’’ For Pollard, other-regarding tendencies have enough that most, if not all of our species’ genomes are there to be focused on the need for ‘altruistic’ panel of experts, find reasonable, and assessed as real biological patterns, cooperators to collaborate.’’ Hawkes succinct enough to be easily digested not as Platonic ideals. Although she narrows the importance of allo- by students first learning about an- cautions that a definition of ‘‘human’’ parental care more specifically to thropology and scholars in other dis- may not have nearly as much to do grandmothers, noting that ‘‘our ciplines with similar interests. We with genetics as was once thought, brains, language, and even pair deeply appreciate the insightful com- she notes that our current view that bonds may depend on the prior evo- ments of each of our contributors, humans are not especially unique as lution of strong appetites for shared making our attempt at this possible. a species genetically could change intentions, with sensitivity to praise We begin with Dr. Weiss’ essay, with novel technologies, which may and blame selected in ancestral given that he poses a critical chal- provide more resolution to genomic youngsters reared in environments lenge to our stated goal, commenting and epigenomic differences between with ancestral grandmothering.’’ that ‘‘even on superficial examina- us and nonhumans. Rosenberg focuses on the ‘‘direct tion,’’ it’s not a meaningful question. As might be expected from a pri- consequences of the human birth His reasoning is important and well- matological perspective, Dr. Sussman pattern’’ and acknowledges the taken. We should not view all emphasizes the fact that humans unique human social ties and behav- humans as conforming to a ‘‘Platonic have ‘‘different ethograms’’ from iors we have in support of childbirth ideal,’’ in search of the essence of nonhumans. While recognizing many and child rearing. humanity. Instead, we must account similarities with our close relatives, Hrdy makes a compelling conclu- for individual variation over time and he notes ‘‘profound behavioral differ- sion that ‘‘long before the evolution space, recognizing that the sum of ences,’’ and that the totipotentiality of behaviorally modern humans ca- being human is greater than the of behaviors for each species differs. pable of symbolic thought and lan- parts. At the same time, however, we Most relevant and uniquely human guage, and even before anatomically respectfully disagree that the ques- in his comparison of behavioral toti- modern big-brained humans, emo- tion lacks meaning, for the very rea- potentiality are ‘‘symbolic behavior, tionally modern hominins already son he uses later: ‘‘Clearly, humans language, and culture.’’ Similarly, psychologically different from other are something different from any- Drs. Seyfarth and Cheney contend apes would have been questing for thing else....’’ We recognize that each that ‘‘fully evolved language provides intersubjective engagement.’’ Pre- individual is unique and that boun- the most striking difference between sumably such hominins would have daries of humanity are blurred over modern human and nonhuman pri- had language ‘‘perception’’ abilities time, but feel it is unwise for evolu- mates.’’ Specifically, they argue that similar to those of humans, but tionary anthropologists to respond to two features of cognition and com- lacked our language ‘‘production’’ a question of such great human in- munication limit the other primates skills, as noted by Seyfarth and terest by implying ‘‘bad question, and make us unique: our full blown Cheney. This further illustrates the please move along.’’ Indeed, our theory of mind and flexible vocal impossibility of clearly demarcating response to his query ‘‘Is this a production. human from nonhuman in an evolu- humanistic rather than scientific Dr. Campbell’s neuroanthropologi- tionary sense, even though clear dif- question?’’ would be that it is both a cal perspective on cognition and ferences between humans and our humanistic and a scientific question, communication is in harmony with closest relatives exist today. Thus, we and exactly why an anthropological the views of our primatologists, as are rightly reminded by Drs. Stiner perspective is vital to the discussion. he contends that we have ‘‘a brain and Kuhn that as intuitively appeal- Weiss’s comment that there is ‘‘no that has evolved under social pres- ing as it is to see ourselves as such thing’’ as the human genome sure to make us self-aware individu- unique, ‘‘claims of absolute breaks 194 ISSUES with other life forms are impedi- nating from diverse research per- between living humans and nonhu- ments to learning how humans spectives within evolutionary anthro- mans must have emerged in a con- developed their remarkable facility pology (see Whiten and Erdal1 for a tinuous way over time). Our contrib- for and dependence on culture.’’ similar and well-reasoned conclu- utors demonstrate our biocultural Finally, Drs. Cartmill and Brown sion). Our language abilities, social nature eloquently in varied ways, return to a theme of Weiss, noting interaction, symbolic behavior, and and much of evolutionary anthropol- that ‘‘Which of our peculiarities give cultural variation all seem tied to our ogy makes this point, directly or oth- humanity its unique importance and desire to understand the minds of erwise. significance?’’ is not an empirical others, for both cooperative and self- These two human attributes have question, but still an interesting one. ish reasons. It is this cultural and led to our being a hugely influential They emphasize two key human cognitive reality, lived simultane- part of nature, and how we define universals: ‘‘our unique propensity ously through social, linguistic, sym- ourselves can have great consequen- for imitation’’ and ‘‘seeing things bolic, and evolutionary contexts, that ces for our entire planet. Are we from the other fellow’s perspective.’’ makes humans truly distinct from masters of the universe or something Importantly, they also remind us that other beings on the planet. We are more nuanced and complicated? ‘‘we are the ones who have to make not ‘‘ignoring the evolutionary sub- Much of academia and the public at the decisions that will preserve this strate of our own unique cognitive large want answers. Evolutionary symbiosis or bring it crashing evolution,’’ as Stiner and Kuhn warn anthropologists have a central toolkit down — and us along with it.’’ against, but using comparisons with to bring to bear on this topic. We So what do we as evolutionary other species to understand differen- have to be ready to participate in anthropologists tell inquiring minds ces in the ‘‘totipotentiality’’ of human an open and engaged discussion, who seek an answer to ‘‘What makes behavior, as Sussman suggested. regardless of what we think of the us human?’’ We all certainly can Nonhuman primates surely show particulars of the questions (or agree that an evolutionary perspec- signs of empathy, cooperation, and answers!). By thinking aloud with tive is required. Yet ironically, an imitation,2 which would be expected one another, and maybe even going evolutionary perspective makes the from an evolutionary perspective. beyond the boundaries of our intel- question much more complicated, However, no other species are so lectual comfort zones, we may be because at no point in time can we intensely motivated, both coopera- able to enrich our own research ever point to one generation of tively and competitively, to recon- endeavors and contribute in mean- humans whose parents were nonhu- struct their entire environment and ingful and lasting ways to how peo- mans. We are connected to other live their lives based on their con- ple think, not only about becoming species in many ways. Thus, great cerns with the mind of others. human, but about being human. caution is urged when trying to dis- Second, and as the direct result of tinguish us from all other species our first point, we are biocultural without recognizing the core con- animals.3,4 As Marks5 recently eluci- tinuities. However, there clearly is dated, no other species has evolved something distinctive about humans as we have: human evolution is not REFERENCES today as opposed to other living spe- simply a biological process, but truly 1 Whiten A, Erdal D. 2012. The human socio- cies. As Rosenberg stated, ‘‘consid- a biocultural process. Our biology cognitive niche and its evolutionary origins. ering those factors in which we are cannot be understood outside of the Phil Trans R Soc B 367:2119–2129. 2 de Waal FBM, Ferrari PF, editors. 2012. distinct elucidates significant aspects aforementioned cultural and cogni- The primate mind: built to connect with of the human adaptation.’’ We pro- tive reality, and culture cannot be other minds. Cambridge: Harvard University pose that these essays, and our own fully understood without biology. Press. views, point to two key factors that Thus, our biology and culture are 3 Calcagno JM. 2003. Keeping biological an- thropology in anthropology, and anthropology make us human. not just intertwined, but melded to- in biology. Am Anthropol 105:6–15. First, humans are characterized by gether, co-existent, inseparable. Evo- 4 Fuentes A. 2012. Race, monogamy and other a fully developed theory of mind, lution is about both continuities and lies they told you: busting myths about human with the ability for flexible language discontinuities. Our biocultural na- nature. Berkeley: University of California Press. 5 Marks J. 2012. The biological myth of human skills and the concomitant symbolic ture is the core discontinuity that evolution. Contemp Soc Sci 7:139–157. and global reality of culture. This is emerges in our evolutionary history a common theme among essays ema- (even though this discontinuity VC 2012 Wiley Periodicals, Inc.