PSRXXX10.1177/1088868316657965Personality and Social Psychology ReviewBalliet et al. 657965research-article2016 Article Personality and Social Psychology Review 1 –28 Functional Interdependence Theory: An © 2016 by the Society for Personality and Social Psychology, Inc. Reprints and permissions: Evolutionary Account of Social Situations sagepub.com/journalsPermissions.nav DOI: 10.1177/1088868316657965 pspr.sagepub.com Daniel Balliet1, Joshua M. Tybur1, and Paul A. M. Van Lange1 Abstract Social interactions are characterized by distinct forms of interdependence, each of which has unique effects on how behavior unfolds within the interaction. Despite this, little is known about the psychological mechanisms that allow people to detect and respond to the nature of interdependence in any given interaction. We propose that interdependence theory provides clues regarding the structure of interdependence in the human ancestral past. In turn, evolutionary psychology offers a framework for understanding the types of information processing mechanisms that could have been shaped under these recurring conditions. We synthesize and extend these two perspectives to introduce a new theory: functional interdependence theory (FIT). FIT can generate testable hypotheses about the function and structure of the psychological mechanisms for inferring interdependence. This new perspective offers insight into how people initiate and maintain cooperative relationships, select social partners and allies, and identify opportunities to signal social motives. Keywords interdependence, power, conflict, cooperation, evolution Interdependence is the greatest challenge to the maturity of behavior affects their own and others’ outcomes—can pro- individual and group functioning. vide key insights into how organisms are adapted to the social —K. Lewin; Marrow (1969, p. 226)1 environment (e.g., Roberts, 2006; Tomasello, Melis, Tennie, Wyman, & Herrmann, 2012; Tooby & Cosmides, 1996). To The demands of interdependent social life that “select” for illustrate, evolutionary biologists argue that corresponding certain behavior tendencies in the course of an individual’s life versus conflicting fitness outcomes between individuals can may also have selected genetically for humans with those determine whether cooperation evolves in a species (e.g., tendencies or, at least, with the aptitude for readily learning Hamilton, 1964; Trivers, 1971). Although this work has not them. always focused on humans, it implies that different forms of human interdependence in the ancestral environment would —Kelley and Thibaut (1978, p. 181) have produced psychological adaptations for navigating interdependence (Doebeli & Hauert, 2005; Skyrms, 2004; We operate in a world where the inferred costs and benefits of Tomasello et al., 2012). Hence, understanding how humans actions are relevant to our understanding of our exchange relations. deal with Lewin’s great challenge of interdependence requires —Tooby, Cosmides, and Price (2006, p. 118) a consideration of not only contemporary social environments but also the ancestral past and the types of adaptations that Interdependence provides significant opportunities and chal- underlie our psychology of interdependence. lenges to any organism. This is especially the case for But what was the form of interdependence in the ancestral humans, given the richness of our social lives. Indeed, Lewin, past? And what adaptations might have evolved in response a pioneer of social psychology, suggested that navigating the to these types of interdependence? Here, we answer both of landscape of interdependence is a foundational challenge to these questions by detailing the fundamental structures of group and individual functioning (Marrow, 1969). Seventy interdependence proposed by Kelley and Thibaut (1978) and years later, Lewin’s observation seems prescient given the the types of information processing systems these structures volume of biological and social science work dedicated to understanding how interdependence shapes human behavior 1VU Amsterdam, The Netherlands (e.g., Emerson, 1976; Kelley et al., 2003; Maynard-Smith, 1974; Montgomery, 1998; Olson, 1965). Corresponding Author: Daniel Balliet, VU Amsterdam, Van der Boechorststraat 1, 1081 BT Recent biological perspectives on social behavior suggest Amsterdam, The Netherlands. that interdependence—the manner in which each individual’s Email: [email protected] Downloaded from psr.sagepub.com at Vrije Universiteit Bibliotheek on July 27, 2016 2 Personality and Social Psychology Review should have produced using Tooby and Cosmides’s (1992) implausible that the mind has evolved for the general func- approach to understanding psychological adaptations. This tion of “engage in fitness-promoting behavior” (or, pertinent integration can be used to generate novel hypotheses regard- to this article, “navigate interdependence”; Cosmides & ing the function and structure of psychological mechanisms Tooby, 1994a; Kurzban, 2010). One of the key contributions for detecting and responding to the specific types of interde- of evolutionary psychology concerns the emphasis on func- pendence within social situations. We argue that this approach tional specialization of psychological mechanisms (fre- advances evolutionary social psychology by unifying several quently referred to as “modularity”; Barrett & Kurzban, research topics (e.g., cooperation, coordination, power, non- 2006; Cosmides & Tooby, 1994b). The varied nature of verbal behavior, and emotional expressions) under a com- adaptive problems favors the evolution of specialized psy- mon theoretical framework. Before outlining our theory, chological mechanisms, each of which processes specific though, we briefly describe the theoretical foundations of information in a functional manner. evolutionary psychology and interdependence theory. But what are these environmental barriers to ultimately reproducing that have shaped psychological mechanisms? Evolutionary Psychology: Adaptations Evolutionary psychologists, following Bowlby (1969), sug- for Interdependence and Cooperation gest that psychological adaptations (i.e., functionally spe- cialized mechanisms) were shaped by conditions in their Evolutionary theory forms the foundation of scientific inves- EEAs (Tooby & Cosmides, 1990, 2005). Each specialized tigations of interdependence, social interaction, and coopera- psychological mechanism can, theoretically, be shaped in tion across disciplines (Alcock, 2001). Population biologists and by a different EEA. The EEA for mechanisms underly- use evolutionary game theory models to understand how the ing snake detection and avoidance, for example, concerns the structure of organisms’ interdependence can select for coop- environmental conditions in which snakes threatened our erative tendencies (West, El Mouden, & Gardner, 2011); hominid ancestors (Öhman & Mineka, 2001), whereas the ethologists study how different social environments and EEA for mechanisms underlying anticuckoldry adaptations ecologies give rise to varied cooperative strategies across involves environments of paternal investment mixed with taxa (Wilson, 2012); human behavioral ecologists examine extra-pair sex (Buss, 2006). Based on knowledge of the how humans cooperate to solve various interdependent prob- ancestral past, evolutionary psychologists often generate and lems, including hunting, coalitional aggression, and child test hypotheses about the ultimate, fitness-relevant function care (Alvard & Nolin, 2002; Hrdy, 2007; Mathew & Boyd, and proximate, information processing structure of modern 2011); and social psychologists use evolutionary theory to psychology. understand the psychological mechanisms underlying social Although these principles have led to novel predictions interactions (DeScioli & Kurzban, 2013; Kenrick, Li, & and new information regarding the nature of prejudice Butner, 2003; Neuberg & Schaller, 2014; Simpson & (Schaller & Neuberg, 2008), emotion (Tybur, Lieberman, Gangestad, 2001). Kurzban, & DeScioli, 2013), visual perception (Jackson & Each approach aims to understand a fundamental ques- Cormack, 2007), morality (DeScioli & Kurzban, 2013), tion about interdependent biological organisms: How would cooperation (Delton, Cosmides, Guemo, Robertson, & selection favor adaptations that motivate organisms to coop- Tooby, 2012), and aggression (Sell, Tooby, & Cosmides, erate, and so incur costs to provide benefits to others? And, 2009), they have also been criticized on theoretical and especially importantly for psychologists, how would these empirical grounds. Criticisms regarding functional special- (psychological) adaptations be executed? The evolutionary ization have highlighted that “domain general” mechanisms psychology paradigm articulated by Tooby, Cosmides, and (e.g., working memory) can be used in a fitness-promoting others provides a framework for understanding how psycho- fashion (Laland & Brown, 2011). However, the evidence for logical adaptations have been shaped by natural selection to functionally specialized mechanisms is strong (see Kurzban, promote cooperation (Buss, 1995; Symons, 1990; Tooby & 2010; Pinker, 1997, for overviews), and mechanisms need Cosmides, 1992). We discuss two theoretical principles of not be applied to only one adaptive problem to be function- evolutionary psychology that are pertinent to our theory: the ally specialized (e.g., Barrett & Kurzban, 2006). concept of functional specialization and the concept of the Other criticisms have highlighted