Essay Darwin in Mind: New Opportunities for Evolutionary Psychology Johan J. Bolhuis1*, Gillian R. Brown2, Robert C. Richardson3, Kevin N. Laland4* 1 Behavioural Biology Group and Helmholtz Institute, Utrecht University, Utrecht, The Netherlands, 2 School of Psychology, University of St Andrews, St Andrews, Scotland, United Kingdom, 3 Department of Philosophy, University of Cincinnati, Cincinnati, Ohio, United States of America, 4 School of Biology, University of St Andrews, St Andrews, Scotland, United Kingdom Abstract: Evolutionary Psychology which rapidly became dominated by a pressures acting in ancestral conditions—in (EP) views the human mind as school of thought stemming from the an environment of evolutionary adapted- organized into many modules, each University of California at Santa Barbara ness (EEA)—and are not necessarily adap- underpinned by psychological ad- (see Box 1). The essence of this brand of tive in a contemporary world that has aptations designed to solve prob- Evolutionary Psychology (EP) is neatly changed radically in recent millennia. lems faced by our Pleistocene summarized in the famous quote that ‘‘Our From this vantage point, genetic evolution ancestors. We argue that the key modern skulls house a Stone Age mind’’ [2]. simply could not keep pace fully with the tenets of the established EP para- However, many evolutionarily minded extraordinary rate at which human tech- digm require modification in the psychologists, evolutionary biologists, and nology transformed environments. Tied up light of recent findings from a philosophers of science disagree with the with this notion of adaptive lag (or number of disciplines, including theoretical proposals put forward by the mismatch between our biology and our human genetics, evolutionary biol- Santa Barbara evolutionary psychologists, environment) is an emphasis on evolution- ogy, cognitive neuroscience, devel- and the discipline has been the subject of ary gradualism: evolutionary change, par- opmental psychology, and paleo- intense debates [1,3–13]. Here, we assess ticularly with respect to complex adapta- ecology. For instance, many human genes have been subject to recent the impact of recent developments in tions in the human mind, is deemed to have selective sweeps; humans play an genetics, evolutionary and developmental occurred slowly; too slowly to have led to active, constructive role in co-di- biology, paleoecology, and cognitive sci- significant genetic change in the few recting their own development and ence on EP and then go on to suggest that hundred generations that have elapsed evolution; and experimental evi- these developments provide new avenues since the end of the Pleistocene, or even dence often favours a general for research. since the spread of modern humans around process, rather than a modular the world over the last 50,000 years. account, of cognition. A redefined Reassessing the Major Tenets of Recent developments in human genetics EP could use the theoretical in- Evolutionary Psychology have challenged the concepts of adaptive sights of modern evolutionary bi- lag and gradualism. EP originated in the ology as a rich source of hypothe- EP is encapsulated by four major tenets early 1980s, when our knowledge of the ses concerning the human mind, (see Box 1) that have generated consider- human genome was limited and gradualism and could exploit novel methods able discussion. Here, we argue that all of dominated evolutionary thinking (although from a variety of adjacent research these basic assumptions need to be reas- biologists’ attempts to estimate rates of fields. sessed in the light of contemporary selection in nature were in full flow in the evidence. 1970s [14], leaving the Santa Barbara school’s gradualism assumption conten- The Environment of Evolutionary tious from the outset). Since then, geneti- In the century and a half since Charles Adaptedness and Gradualism cists have not only mapped the genome, but Darwin’s publication of the Origin of Species, EP argues that that human cognitive have devised means for detecting which evolutionary theory has become the bedrock processes evolved in response to selection genes have been subject to recent selection of modern biology; yet, its application to the human mind remains steeped in controversy Citation: Bolhuis JJ, Brown GR, Richardson RC, Laland KN (2011) Darwin in Mind: New Opportunities for [1–13]. Darwin himself wrote of cognitive Evolutionary Psychology. PLoS Biol 9(7): e1001109. doi:10.1371/journal.pbio.1001109 evolution, most notably in The Descent of Man, Published July 19, 2011 where he suggested that like any other trait, Copyright: ß 2011 Bolhuis et al. This is an open-access article distributed under the terms of the Creative human ‘‘mental faculties’’ are the outcome of Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, evolution by natural and sexual selection and provided the original author and source are credited. insisted that they should be understood in Funding: JJB is funded by Utrecht University and by Netherlands Organization for Scientific Research (NWO) lightofwhathecalled‘‘commondescent’’. grants (ALW Open Competition and GW Horizon Programme) (http://www.nwo.nl/). GRB is funded by a This evolutionary interpretation of human Wellcome Trust Career Development Fellowship, UK (http://www.wellcome.ac.uk/). RCR is funded by the University of Cincinnati. KNL is funded by the BBSRC, UK (http://www.bbsrc.ac.uk/) and an ERC Advanced Grant cognition was taken up in the 1980s by http://erc.europa.eu/). The funders had no role in study design, data collection and analysis, decision to publish, contemporary evolutionary psychology, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. Essays articulate a specific perspective on a topic of Abbreviations: AI, artificial intelligence; EEA, environment of evolutionary adaptedness; EP, Evolutionary broad interest to scientists. Psychology * E-mail: [email protected] (JJB); [email protected] (KNL) PLoS Biology | www.plosbiology.org 1 July 2011 | Volume 9 | Issue 7 | e1001109 . Box 1. The Major Tenets of Evolutionary Psychology populations during the Pleistocene epoch (approximately 1.7 million to 10,000 years According to the Santa Barbara school of Evolutionary Psychology (EP), human ago), the abstract concept of stable selec- minds are organized into a large number of evolved psychological mechanisms— tion pressures in the EEA is challenged by psychological adaptations designed to solve recurrent problems faced by our recent evidence from paleoecology and hunter-gatherer ancestors [30]. These evolutionary psychologists attempt to paleoanthropology. The Pleistocene was provide criteria for ‘‘carving the mind at its natural joints’’ [104], generally by apparently far from stable, not only being reverse-engineering from an observable phenomenon to its proposed function. variable, but progressively changing in the pattern of variation [25,26]. The world In the 1980s, four major tenets of EP crystallized, and these ideas became experienced by members of the genus widespread. While not all evolutionary psychologists endorse the Santa Barbara Homo in the early Pleistocene was very perspective, these ideas have nonetheless shaped the broader field, and remain different from that experienced in the late extremely prevalent. Pleistocene, and even early anatomical 1. The environment of evolutionary adaptedness (EEA). This concept refers to the modern Homo sapiens that lived around notion that our psychological mechanisms have evolved in response to stable 150,000 years ago led very different lives features of ancestral environments [87]. While the EEA has frequently been from Upper Paleolithic people (40,000 equated with an African Pleistocene savanna, this version of the concept has years ago) [27–29]. been strongly critiqued [66], and the more recent formulation of the EEA concept presents a broader, less specific theoretical landscape of our past lives, based on Universalism an abstract statistical composite of all relevant past selective environments [105]. EP has also placed emphasis on the concept of human nature, comprising a 2. Gradualism. Evolutionary psychologists argue that minds are built from co- species-specific repertoire of universal, adapted gene complexes that are unable to respond quickly to selection evolved psychological mechanisms, from [105,106]. When combined with the concept of the EEA, gradualism suggests that a childhood fear of strangers, to a cheater- human beings experience an adaptive lag [88], such that evolved psychological mechanisms may not produce adaptive responses in modern human environ- detection mechanism, to a preference for ments that have undergone dramatic recent changes [105]. specific mate characteristics. This putative universal cognition can be rendered com- 3. Massive modularity. Given that different sets of adaptive problems will have patible with the observed diversity in required different computational solutions, the mind is argued to consist human behaviour by recourse to context- predominantly of domain-specific, modular programmes [105]. Whether the mind dependent strategies. From this perspec- also contains evolved general-purpose processes remains debated within EP tive, the mind shifts between pre-specified [104]. behavioural outputs in response to differ- ential environmental influences [30,31]. 4. Universal human nature. The evolved computational