If an evolutionary psychologist says that we expect something to be a widespread property of societies, it isn’t a valid rebuttal to say, “But the Aché of South America didn’t have that property.” That’s like laughing at the warnings on cigarettes because your grandmother smoked until she was 96.
Exactly… especially since different populations have different gene frequences.
There is a false assumption that if a certain trait or preference varies between populations, then it must be culturally influenced, and not related to evolution, such that you can “debunk” evolutionary hypotheses for a trait/preference by showing that it varies between populations. Here is an example of that false assumption from WrongBot’s post:
This more than anything else is its failure: it does not acknowledge the mutability of human preference. The current mainstream American standard of female beauty values low body fat, which is a powerful signal of something about genetic fitness. Not long ago, the mainstream Mauritanian standard of female beauty valued obesity (as some subpopulations still do), which is a powerful signal of something contradictory about genetic fitness. No evo-psych theory should be able to explain both of these desirability criteria in a fashion more direct than “desirability criteria are easily influenced by social pressures.”
There is no necessary contradiction here. It’s not surprising at all from the standpoint of evolutionary theory that there should be some variation in preferences between geographically isolated populations. Difference areas with different ecology will have different selection pressures, so which traits lead to “genetic fitness” may differ between areas. As a result of this differing selection pressures, populations that were geographically isolated for long enough could evolve different traits, and preferences for different traits in their partners.
The fact that a certain trait varies between different populations with different ancestry is only weak evidence against an evolutionary factor in that trait, and weak evidence for a cultural hypothesis (these hypotheses are not, of course, mutually exclusive). Different genetic backgrounds and selection pressures between the populations could be the underlying third variable that explains both the difference in traits between two populations, and the differences in cultures and culturally-encouraged preferences.
What would be more impressive evidence against an evolutionary hypothesis, or for a cultural hypothesis, is if the trait varies between two different measures of one population at different times (accompanied by documented cultural changes within that population), or if the trait varies between two different populations with similar ancestry.
So far as I’m aware, the Aché are the only partible-paternity-believing culture for which we have those kinds of of statistics. More data would be better, yes, but I’m not inclined to throw out what we have because there isn’t more of it.
If an evolutionary psychologist says that we expect something to be a widespread property of societies, it isn’t a valid rebuttal to say, “But the Aché of South America didn’t have that property.” That’s like laughing at the warnings on cigarettes because your grandmother smoked until she was 96.
Exactly… especially since different populations have different gene frequences.
There is a false assumption that if a certain trait or preference varies between populations, then it must be culturally influenced, and not related to evolution, such that you can “debunk” evolutionary hypotheses for a trait/preference by showing that it varies between populations. Here is an example of that false assumption from WrongBot’s post:
There is no necessary contradiction here. It’s not surprising at all from the standpoint of evolutionary theory that there should be some variation in preferences between geographically isolated populations. Difference areas with different ecology will have different selection pressures, so which traits lead to “genetic fitness” may differ between areas. As a result of this differing selection pressures, populations that were geographically isolated for long enough could evolve different traits, and preferences for different traits in their partners.
The fact that a certain trait varies between different populations with different ancestry is only weak evidence against an evolutionary factor in that trait, and weak evidence for a cultural hypothesis (these hypotheses are not, of course, mutually exclusive). Different genetic backgrounds and selection pressures between the populations could be the underlying third variable that explains both the difference in traits between two populations, and the differences in cultures and culturally-encouraged preferences.
What would be more impressive evidence against an evolutionary hypothesis, or for a cultural hypothesis, is if the trait varies between two different measures of one population at different times (accompanied by documented cultural changes within that population), or if the trait varies between two different populations with similar ancestry.
AFAIK low body fat was not an attractive trait in the Western societies before the 20th century, either.
So far as I’m aware, the Aché are the only partible-paternity-believing culture for which we have those kinds of of statistics. More data would be better, yes, but I’m not inclined to throw out what we have because there isn’t more of it.