Cross-cultural evolutionary psychology

• Widespread variation exists across human societies.
• Cross-cultural variation can be used to test evolutionary psychological hypotheses.
• Consideration of methodological validity in cross-cultural studies is paramount.
• Large, publically available datasets should be created for future comparisons.

Perhaps no field of psychology is more strongly motivated and better equipped than evolutionary psychology to respond to the recent call for psychologists to expand their empirical base beyond WEIRD (Western Educated Industrialized Rich Democratic) samples. Evolutionary psychologists have historically focused their efforts on identifying species-specific psychological traits, for which evidence often hinged on the extent to which traits were generalizable across human groups. Now, a new generation of researchers is embracing cultural and environmental variation to test evolutionary hypotheses. Here we discuss how comparative research with diverse societies, while challenging, can help inform the complex nature of our species’ psychology and in doing so, we outline best theoretical and methodological practices as well as common pitfalls in cross-cultural investigations. We end with a recommendation for the use of publicly available databases for cataloging psychological variation across the world's many diverse populations. Because of rapid culture change and globalization, it is more important now than ever to document what we know about the world's cultures in ways that can be used by future researchers.