This is a brief response to Almost Diamonds blog responding to Pinker on evo psych.
Yes, using a Western undergraduate psychology sample to represent all of humanity is problematic for evolutionary psychology, but:
1) Using a biased sample to represent the population is problematic for any form of psychology, or any form of social science for that matter. It’s not just problematic specifically for evolutionary psychology.
2) Evolutionary psychologists do not claim that any behavior represents all “humanity” (and more importantly, no psychology field would make such an old, outdated claim). This is certainly a misrepresentation of evolutionary psychology. The field of evolutionary psychology is based on the fact that the human mind houses mechanisms that require input to produce output. For example, if you have the input of hunger, than you produce the output of eating food. Therefore, if you change the input (e.g., changing the culture), then you will produce a different output (e.g., different behaviors between different samples and countries). Certainly, non-university students experience different inputs than university students, and so we would of course expect differences between two such samples. The key to social science is to see if those differences are meaningful at a statistical level. In other words, are differences between two samples of a magnitude that is greater than you would expect by chance alone?
3) Many studies do not exclusively use undergraduate psych majors at Western universities. Many recruit from US and German schools, as well as from the general public.
4) The study sample is less of a problem in many cases because students at universities in California (for example) come from diverse racial, ethnic, and cultural backgrounds. Also, experiments are less problematic than studies that employ survey methodologies. Rather than generalizing about broad characteristics, many examine responses to controlled stimuli.
5) Many patterns examined in many studies had been observed using other methods in countries and cultures around the world; so many studies are not “stand alone” documents in this regard, but serves to provide part of a bigger picture about how people respond to gender ratios (for example) in their environment (real or perceived).