by Rebecka K. Hahnel-Peeters
There are many disciplines, subdisciplines, and paradigms through which to understand human behavior – two of which are evolutionary anthropology (EA) and evolutionary psychology (EP). At its core, the goal of EP is to understand the design features of the human mind shaped by natural selection to solve adaptive problems produced over evolutionary time (for review see Buss, 1995; Daly & Wilson, 1997). In a similar manner, EA uses the lens of evolutionary theory to analyze human behavior (both past and present; Fessler et al., 2016). Both EA and EP use the environment of evolutionary adaptiveness (Tooby & Cosmides, 1990) to inform theories of possible psychological mechanisms. However, EA and EP were founded on differing assumptions, and competition between these disciplines was motivated by (1) the differences in assumptions, (2) empirical methodology, and (3) limited time and resources to establish each discipline as serious scientific pursuits (Alden Smith, 2000)—all of which I review in depth here.
What are the similarities and differences between Evolutionary Anthropology and Evolutionary Psychology?
Similarities between the two disciplines include the study of human behavior, emotion, and cognition informed by adaptationist thinking; using comparative animal behavior to understand our behavior; and recognizing the importance of testing hypotheses in environments more like those of our ancestral past (Fessler et al., 2016). Notably, researchers in both disciplines hold adaptive behavior resulting from mechanisms shaped by selective pressures reliably linked to distinct adaptive challenges (Barrett, 2015; Fessler, 2006).
Differences between the two fields have been characterized most heavily by methodology. In many subdisciplines of EA, the focus of study has been on behavioral variance rather than the design features of the psychological mechanisms which produce our behavior (Alden Smith, 2000). Therefore, the main difference between EA and EP are their differing focal points (i.e., behavioral variation in different ecologies vs. the structure of cognitive mechanisms). This led to the differences in methodologies that characterize the fields today (e.g., anthropological field work and psychological lab experiments).
Evolutionary Anthropology and Psychology Are Complimentary
Since Alden Smith (2000) argued that EA and EP shouldn’t be considered competing disciplines and the recent 10th anniversary of Henrich et al.’s (2010) “the WEIRDEST people in the world” paper presented good reason to assess the state of the evolutionary social sciences, I conducted a content analysis of articles published in our society’s flagship journal. Henrich et al. (2010) highlighted a problem that most psychological research was based on WEIRD societies; because of this, we may expect increased collaborations between EA’s and EP’s in tests of evolutionary theories cross-culturally following the article’s publication.
Have Evolutionary Anthropologists and Evolutionary Psychologists become more collaborative?
Based on publications in EHB: not really (Figure 1). Across the 737 articles published between 2009 and 2020 there doesn’t seem to be an increase in collaborations between anthropologists and psychologists. In 2009, collaborations between anthropologists and psychologists accounted for 15.8% (n = 6) of the publications. The following years included between 2% and 18% of the publications with the mean rate of collaborations being 9.68% (n = 5.8).
How do evolutionary anthropologists and psychologists study phenomena?
Both use behavioral data and a variety of methods. Evolutionary anthropologists and psychologists do not appear to differ much in their use of behavioral data; however, the methods used to get these data were statistically different. There were significant differences in the methods used by anthropologists and psychologists. Anthropologists were more likely to use survey methods and field work than psychologists, and psychologists were more likely to use experiments in artificial environments (e.g., labs). Interestingly, it appears that psychologists started utilizing more methods to test their hypotheses after 2010. The variation in methodology started looking more like that of anthropologists (Figures 2 & 3).
In the preprint, I discuss this project more in depth – including methodology, limitations, and future directions to understand the state of the evolutionary social sciences.
Interdisciplinary research—especially between complimentary disciplines—can strengthen our understanding of the world around us. EA and EP are uniquely positioned for collaboration, but the current state of EHB doesn’t show high levels of explicit collaboration between anthropologists and psychologists. It is possible that these two disciplines are becoming more collaborative implicitly; that is, they may be citing each other more, influence each other’s research questions and hypotheses, or evolutionary anthropologists may be training evolutionary psychologists (or vice versa).
Finally, we should continue to consider a roadmap for future collaboration suggested by Fessler et al. (2016). These four steps are attainable and could result in meaningful contributions to the field:
- Take advantage of existing literature within paleoanthropology and comparative animal behavior
- Read, cite, and understand ethnographic depictions of small-scale societies
- Utilize the electronic Human Relations Area Files
- Increase collaborations between evolutionary anthropologists and psychologists