A periodic table of evolved psychological adaptations.
Posted Sep 19, 2018
(This is a special version of Darwin's Subterranean World that is co-written by Olivia Jewell (Associate Project Manager for PsychTable) and Glenn Geher)
Here are some things we know about being human based on thinking of our evolved psychology in terms of evolved psychological adaptations (EPAs):
- Humans show a strong pattern of nepotism when it comes to who helps whom in emergency situations (see Burnstein, 2005).
- A waist-to-hip ratio of approximately .7 in women is found as optimally attractive (and it corresponds to fertility; see Platek & Singh, 2010).
- Our ability to process information logically increases when stimuli are presented in terms of whether someone has cheated on a social contract (Cosmides & Tooby, 1992).
And more! In fact, a large part of the entire field of evolutionary psychology focuses on EPAs. Understanding how certain species-typical behavioral attributes helped our ancestors to survive and/or reproduce is a basic goal of evolutionary psychology (see Geher, 2014).
A few years ago, a member of our lab, Dan Glass, brought a unique and ambitious idea to a lab meeting. Dan called the idea, which was co-developed equally by his collaborator Niruban Balachandran (see Balachandran, 2011; Balachandran & Glass, 2012) and was inspired by Leda Cosmides and John Tooby, PsychTable - and discussed it as follows:
This mass collaborative project will be the first comprehensive database to classify, compile, and organize proposed human Evolved Psychological Adaptations (EPAs) onto a dynamic platform optimized for scientific evaluation and research.
Wow, Niruban and Dan - this is one of those obviously great ideas that we wish we had come up with first!
As members of the PsychTable team (Olivia is Associate Project Manager and Glenn is a member of the senior advisory board), we write here to describe this project, including ways that YOU might get involved!
What is PsychTable?
PsychTable is the world's first classification table for evolved psychological adaptations (EPAs).
An EPA is a species-typical behavioral or cognitive trait which has been shaped by the process of natural selection, because of genetic fitness benefits it conferred to its bearers over the course of evolutionary time.
EPAs that have been documented by researchers in the field of evolutionary psychology include, for instance, the following list:
- wariness around snakes
- physical pain
- color vision
- core disgust
- sense of number
- recognition of facial expressions
- anti-predator directed gaze reflex
- incest avoidance bias
- preference for low morphological fluctuating asymmetry
- genetic relatedness-induced bias for altruism toward kin
- language acquisition device
- optimal foraging bias
- gustatory sugar detection
One major criticism of this adaptationist approach, which is dominant in the field of evolutionary psychology, is that evolutionary psychologists might get so excited about the concept of adaptation that they tend to over-utilize the concept. In effect, the criticism is that evolutionary psychologists think that there are more behavioral adaptations than is actually the case. Further, such critics (e.g., Grossi, 2014) suggest that the evidence for the existence of psychological adaptations may actually be weak.
OK - we’ve heard the criticisms. And you know what? We think that there may be something to it! In fact, good science always advances from alternative views and from pushes toward more and better-quality data.
PsychTable, in fact, is fully rooted in this premise.
How PsychTable Works
By design, PsychTable takes a critical approach to the idea of an EPA. It works like this: Someone proposes an EPA and submits it for inclusion in PsychTable. The managers of the database, upon seeing some data to support the case for that particular EPA, will include that EPA in PsychTable. At that point, a careful, world-wide scrutiny of that EPA commences. People who have research-based citations that either support or dispute the existence of that particular EPA can upload the citations. As more citations come in, a clear majority will eventually emerge. Some proposed EPA might have, for instance, 19 peer-reviewed articles supporting the existence of that EPA as a clearly evolved adaptation, while there may be only 2 peer-reviewed articles that empirically take issue with the claim.
Further, the managers of PsychTable will work to integrate and arrange the various EPAs in a coherent organizational scheme. EPAs related to mate attraction will cluster together. EPAs regarding kin-detection mechanisms will cluster together, and so forth.
Ultimately, this database will be a world-wide-peer-reviewed collection of information speaking to the evidence underlying the evolved psychological adaptations that serve as the foundation for what it means to be human. Further, the degree to which the various adaptations actually are scientifically validated as Darwinian adaptations will be indicated, providing important information speaking to just how certain we can be that any particular proposed EPA actually is part of our evolved heritage.
Hats off to Niruban Balachandran And Dan Glass - a couple of renegade young academics looking to create something great! Still in its early stages, we are confident that PsychTable is exactly the kind of forward-thinking, data-based, big-picture idea that has the capacity to push the needle in a big way. A large-scale, peer-reviewed, open-access database of human evolved psychological adaptations has the capacity to help advance our understanding of what it means to be human. Check out the website for more information - including how YOU can get involved!
*claps to rogue behavioral scientist, Michael Mills, for advancing this concept early on and for his continued support of the project.
Balachandran N. A proposed taxonomy of human evolved psychological adaptations. J Soc Evol Cult Psychol. 2011; 5(3):194–207.
Burnstein, E. (2005). Altruism and genetic relatedness. In D. M. Buss (Ed.), The Handbook of Evolutionary Psychology. New York: Wiley.
Cosmides, L. & Tooby, J. (1992). Cognitive adaptations for social exchange. In J. Barkow, L. Cosmides, & J. Tooby (Eds.), The adapted mind: Evolutionary psychology and the generation of culture. New York: Oxford University Press.
Geher, G. (2014). Evolutionary Psychology 101. New York: Springer.
Grossi, G. (2014). A module is a module is a module: Evolution of modularity in Evolutionary Psychology. Dialectical Anthropology, 38(3), 333-351.
Platek, S. M., & Singh, D. (2010). Optimal waist-to-hip ratios in women activate neural reward centers in men. PLoS ONE 5: e9042.