One of my favorite websites is Rotten Tomatoes, which aggregates movie reviews from all major (and some minor) print and online sources, to create — for each film — a bottom-line “consensus,” as well as a percentage score of positive vs. negative reviews (where 100% signifies that all reviews for that movie were positive). This percentage score can be seen as a proxy for how likely any given person is to enjoy the film (and as such is more informative than any single movie review) — or more crudely, how “good” the film is.
PsychTable.org is a new collaborative web project which applies the same principle to research papers in the domain of the evolutionary behavioral sciences, combined with elements of Wikipedia and the Periodic Table of the Elements. And if I do say so myself, I think PsychTable has the potential to be a tremendously useful tool for the evolutionary social sciences.
The rationale behind PsychTable’s creation is fairly straightforward: evolutionary psychology (I use the term broadly to include all approaches to understanding the brain and mind which incorporate evolutionary perspectives) generally posits a collection of species-typical behaviors and cognitive processes which are under some degree of genetic control and are what entails (in our species) the human — as opposed to, say, the mongoose — mind. These mental processes are known by a variety of names depending on the particular academic discipline and theoretical orientation, with slightly varying definitions accompanying the various terms, but two of the most common are modules and evolved psychological adaptations (EPAs).
All fine, but — and here’s the big issue — there is no system of organization to compile the EPAs discovered up until now, no taxonomy to lay out, in one central location, the state of our combined knowledge of which particular discrete, domain-specific information processing systems the human mind contains. To make matters worse, not everyone who studies the human mind even agrees that it is comprised, in part or in whole, by discrete, domain-specific modules of this type. Finally, even among the community of researchers who believe that the mind is modular (or, perhaps more generally, is comprised of specific “evolved psychological adaptations”) it’s still not always clear which proposed EPAs are strongly empirically supported and which are lacking in evidence. Most researchers who study the mind would agree that that there are a number of dedicated modules underlying the visual system, but is there a module dedicated to assessing females’ waist-to-hip ratio? Many evolutionary psychologists would say yes, but there is a great deal of controversy outside mainstream evolutionary psychology (and a bit within it) about whether this purported EPA (not to mention many others) exists.
Up til now, the way to approach a disagreement between two researchers about whether humans are evolved to detect optimal waist-hip ratios has been something like the following: Person A cites the seminal studies supporting the this particular EPA. Person B claims those studies are flawed for reasons explained in Paper X and points to Studies Y and Z which conclusively demonstrate that the behavior in question — in this case, preference for a low/optimal waist-hip ratio in female partners — is not an EPA. Person A says s/he has never heard of these papers, and Person B vows to send the papers to Person A, which s/he never does. Neither party is convinced, and the process repeats next time each person meets another with a conflicting viewpoint. As much fun as this process sounds, it’s almost completely useless to the scientific endeavor, and it gets mind-numbingly tedious after awhile.
Enter the evidentiary evaluation system of PsychTable.org, which aggregates both supporting and challenging citations for each proposed EPA and generates a final score — a la Rotten Tomatoes — that shows how strongly each candidate EPA is supported in the literature. In so doing, PsychTable creates a database of each proposed EPA in the literature and how much evidence exists to support it, how much it’s lacking, and/or whether its existence has been strongly refuted. The site also outputs a “table” (hence the name PsychTable) showing the most firmly supported of the EPAs and their relationships to one another.
This is where the “collaborative” part comes in…the scores for each study/citation come from expert contributors, or “curators” in PsychTable parlance — a network of collaborators all around the world with knowledge and experience in the relevant fields, who are equipped to make judgments on how convincingly each study demonstrates or challenges the existence of the EPA in question.
But how exactly does one demonstrate evidence for an EPA? Luckily, a system toward this end has already been devised, by David Schmitt and June Pilcher in their seminal 2004 paper entitled “Evaluating evidence of psychological adaptation: How do we know one when we see one?” In it, Schmitt and Pilcher argue that the best way to support a claim that a behavior is an evolutionary adaptation is to marshal support from eight distinct lines of evidence: theoretical, psychological, physiological, medical, genetic, phylogenetic, cross-cultural, and hunter-gatherer. Read their fine paper for more details, but the point is that methodologically and theoretically sound support from most or all of these domains can, together, suggest that a trait is an evolved psychological adaptation, even though one study alone can rarely rise to this burdensome task.
While Schmitt and Pilcher’s paper was well-appreciated by the field, to my knowledge there has been no widespread attempt to systematically apply their framework to the existing proposed EPAs within the evolutionary social sciences…until now. PsychTable uses the “lines of evidence” system as its basis, such that a curator can decide, for each study, how well it supports or challenges the existence of the EPA from each of the eight lines of evidence. These scores are aggregated for all the raters, creating a “peer-consensus” score for each study/citation, which is then put into an algorithm which assigns a final “strength” score for the EPA. This final score, which ranges from 0 to 100, shows how robust the evidence is for each EPA; EPAs with relatively high scores (I would expect the rooting reflex and our visual edge detector system would fall into this category, for example) are graphically displayed in the table with highly opaque symbols, while relatively more weakly supported EPAs (I refuse to accidentally make enemies by naming some, even though no judgment would have been intended) are shown as more transparent (see below). Purported EPAs with very little support behind them aren’t shown on the table at all, but they can be viewed in a “Recycle Bin”-type section of the site, which shows proposed EPAs that have been either conditionally disconfirmed, or simply need more empirical support.
So what’s the point of all this? Firstly, PsychTable provides a method of aggregating supporting and challenging evidence — and thus adjudicating debates about — proposed EPAs in a way that is more productive and permanent than any given heated academic bickering session. Is there robust evidence that men have an evolved preference for young and attractive women? Let’s go to PsychTable and look it up. Don’t agree with the evidence presented on PsychTable? Contribute some of your own (in the form of citations of published, peer-reviewed studies) and/or rate the citations that are already there. As long as both sides of the debate are arguing on the basis of available evidence, PsychTable will appear as an impartial arbiter, chewing up the data and spitting out the results. (Of course, as is often the case, if one or both sides of the argument are utilizing emotional, political, or religious biases as the basis for their claims, well…PsychTable can’t do much about that.)
Secondly, PsychTable will display the current state of knowledge of evolutionary psychology and related fields in an organized fashion that will concretize well-established findings and highlight the areas that need further investigation. This function will serve as a reference for researchers in the field as well as an educational resource for laypeople who wish to learn about the evolutionary social sciences.
Finally, and most critically to the main theme of this blog, the PsychTable process will eventually (given time and a dedicated pool of contributors) result in a product…a dynamic, ever-changing product, but a product nonetheless: a catalog of the functions of the human mind. Sure, some of us can cut detailed paper butterflies out of construction paper, while others can memorize 100-word lists…but what are the universal features of the normally developed human mind? What is the list of psychological tools, modules, adaptations, whatever you call them, that make my mind, your mind, and Mario Van Peebles’ mind human, as opposed to those that make Koko, Flipper, and Spuds McKenzie nonhuman? Aside from the tremendous research and pedagogical potential such a resource would afford research psychology, imagine how it might impact other disciplines such as computer science (think of how an exhaustive catalog of human psychological modules might enhance our ability to build realistic artificial intelligence, for example).
And, of course, imagine the impact on clinical psychology. With a full understanding of the EPAs within the human mind, a truly evolutionary taxonomy of mental disorders would be easily within reach. The status of any symptom set as truly “dysfunctional” would be easily ascertainable, and certain judgments regarding treatment decisions may be clarified. New avenues of treatment entirely may open up. And, yes — while I don’t anticipate this happening — if PsychTable’s evidentiary system ends up revealing a much less rich evolved modular structure of the brain than evolutionary psychologists have been describing all these years, then we proponents of evolutionary clinical psychology will finally shut up about how important it is to understand the brain’s evolved adaptive functioning.
Read all about the details of the PsychTable project in this newly published article in the Evolution: Education and Outreach journal. If you don’t have a Springer subscription, a free (less pretty) version of the article is available here. Then check out the PsychTable.org site…a working beta version is currently in production. Contact me if you’d like to help with the project!