Evolutionary psychology (EP) is not the only approach in understanding human evolved psychological and behavioral mechanisms. In fact two other competing, dominant, or alternative, whatever you would like to call, evolutionary analyses exist- Behavioral Ecology (BE) and Dual Inheritance Theory (DIT). Eric Alden Smith reviewed the differences between them in Adaptation and Human Behavior An Anthropological Perspective, edited by Lee Cronk, Napoleon Changnon and William Irons (Click the review chapter by Smith here (http://faculty.washington.edu/easmith/ThreeStyles.pdf) I think it is interesting because of I myself is quite interested in EP and the distinctions between different approaches Smith described in the chapter is enlightening. I am presenting his analysis in summary points.
1. Foundations of Evolutionary Psychology (EP)
EP embraces these assumptions: modularity, historicity, adaptive specificity and environmental novelty. Modularity is based on specialized cognitive mechanisms, rather than general mechanism i.e. our cognitive abilities have specific functions to solve specific challenges. Historicity refers to the Environment of Evolutionary Adaptedness (EEA) in the past where natural selection shaped these specific cognitive functions we have now. Adaptive specificity means these acquired cognitive abilities produce specific adaptive outcomes like male universal preference for youthful, healthy and beautiful females. Environment novelty refers to the presence in which our cognitive mechanisms are not yet adapted to. There is a delayed adaption because of our adaptive mechanisms acquired possibly in Paleolithic era.
2. Assumption in Human Behavioral Ecology (HBE or BE)
The key assumption of this approach is called piecemeal analytical approach that studied piece by piece in a reductionist way, usually depending on conditional strategies. The approach asks what ecological forces shape and select behavior X. And in context A, produce behavior X, but in context B, switch to Y. The big part focuses on environmental features such as resource density, frequency of competitors, number of populations in say understanding territorial defensive behaviors. Unlike EP, BE focuses behavioral diversity with the emphasis on contemporary environment and its rapid adaptations and changes in phenotype. The approach assumed very little adaptive delay. The approach is somewhat indifferent in emphasizing specific mechanism like modularity and historicity because of the rapid adaptations in contemporary environment.
3. Cultural Focus in Dual Inheritance Theory (DIT)
DIT approach assumes that cultural and genetic mechanisms, as separate but linked, shape behaviors. Cultures are parallel to genes but not qualitatively. Cultures also have variations, heritability, and fitness results. So they can be analyzed using Darwinian approaches but culture transmission can be very dynamic; it includes non-parental transmission and multiple and very rapid transmission events over a life time period. The approach usually uses mathematical modeling and simulation in analyzing large-scale social exchange. The mechanism that the approach usually focuses is the model of cultural group selection such as reciprocity in a group dynamics.
In short, EP links evolved psychological mechanisms, behavioral responses, and past environment stimuli effects on fitness. BE focuses on contemporary environmental stimuli and behavioral responses to fitness results. DIT focuses on cultural and genetic links to psychological mechanisms on fitness effects. They all complement each other, but with distinct assumption on delayed adaption in EP and rapid adaptation in contemporary environment in BE.
EP also uses standard psychological methods such as surveys, and experiment. BE uses more anthropology-oriented approaches such as ethnographic observation. DIT uses assumptions and models in mathematical simulation in a population level.
PS I did not cite the original contributions to many original statements for the article because almost all the words and explanations come directly form original author and his analysis. You can find all the other original authors’ contribution in the link above, as cited in his essay. Thanks to Eric Alden Smith for the insights into 3 different styles of evolutionary analysis. The information definitely adds up to my little knowledge house of evolutionary psychology and broadens my view.