Posts tagged with evolutionary psychology

adults, unlike children, rarely cry in public. They wait until they’re in the privacy of their homes—when they are alone or, at most, in the company of one other adult. On the face of it, the “crying-as-communication” hypothesis does not fully hold up, and it certainly doesn’t explain why we cry when we’re alone, or in an airplane surrounded by strangers we have no connection to…

In the same 2000 study, Vingerhoet’s team also discovered that, in adults, crying is most likely to follow a few specific antecedents. When asked to choose from a wide range of reasons for recent spells of crying, participants in the study chose “separation” or “rejection” far more often than other options, which included things like “pain and injury” and “criticism.”

about a paper by Vingerhoets, Cornelius, Heft, Beck

Towards a Model of Adult Crying

(Source: neuroecology.wordpress.com)




Evolutionary psychology … popular … media … people latch on to these stories and use them to justify the status quo. One … is that men prefer women with small waists and big hips. This is measured using the Waist to Hip Ratio (WHR). The WHR is the circumference of your waist divided by the circumference of your hips. The links below will tell you that men are irresistibly drawn to women with WHRs of .70. This number is apparently imbued with evolutionary significance because prepubescent girls have WHRs close to 1 (their waists are the same size as their hips), while post-pubescent girls have WHR less than 1 (waists smaller than hips); and also because low WHRs are associated with a good hormonal balance. One thing that makes this idea attractive is that it conforms to our modern, western experience—many women who are considered to be extremely attractive have low WHRs and it’s difficult to generate examples of women who are famous for their beauty, but who have high WHRs. …


… here are a couple recent stories about the WHR: 1 (this one includes exercise tips to help women appear to have a more ideal WHR ratio) 2, and 3 (this one also claims that “men’s perfect lovers come with a waist-to-hip ratio of .70”, implying, I suppose that WHR ratio influences how good you are in bed??). Science reporting is rarely subtle and these articles are no exception. They talk about “males”, “females”, “mate preference”, and “evolutionary” indicators of fertility. This language suggests to the average reader that these results are universal. That they reflect the preferences of people in general. But, does the research behind the headlines support this universality?

The burden of any serious evolutionary psychology research program must be to establish the generality of their results across cultures. It doesn’t matter how cool the evolutionary angle is— oh, look, this co-varies with fertility!!. It doesn’t matter how obvious the effect seems to us. If male preference for women with low WHRs doesn’t obtain across cultures then it’s not universal. This isn’t to say that there couldn’t still be an evolutionary component to our preferences. It would be remarkable if there were not. But, genetic contributions to behaviour are complicated. So, failure to establish the generality of a preference for low WHR doesn’t necessarily imply that men aren’t sensitive to information that conveys fertility in potential partners. But, it does mean that there is not a universal reliance on this one particular type of information. It is quite likely that a whole lot of cues interact in a complex system of perceived attractiveness, to the extent that it doesn’t make much sense to isolate one variable. So, anyway…

What IS the evidence for a low WHR … preference across cultures? Well, it’s actually quite muddled. Westman and Marlowe (1999) provide a pretty good intro to the evidence for the WHR preference, so I’d recommend their paper for a quick overview. They point out that the majority of studies on WHR rely on American undergraduates, although there is also evidence for a similar preference in Hispanic, British (although see below), and American-Indonesians. Some researchers (e.g., Singh, 1993) suggest that this preference is universal across cultures (p. 305). But, rather than jump straight into a statement of universality, Singh says something a bit more measured. He claims “the fact that WHR conveys such significant information about the mate value of a woman suggests that men in all societies should favor women with a lower WHR over women with a higher WHR for mate selection or at least find such women sexually attractive.” That last bit is interesting. It merely suggests that men shouldn’t find women with low WHR unattractive. This is a very different argument than the oft repeated universal preference for low WHR.

Unfortunately, Singh’s … prediction has morphed into a presumption of universal preference for low WHR. ….
But, as it happens, there is quite a bit of evidence against this claim. Westman & Marlowe (1999) tested the effect of weight and WHR on perceived attractiveness, health, and suitability as a wife in the Hadza of Tansania. The men in that society showed no preference for women with low (.7) or high (.9) WHR, but they did show a distinct preference for heavier (cf. thin) women. Yu and Shepard (1998) also failed to find an effect of WHR on attractiveness among the Matsigenka. Swami et al (2007) looked at WHR preferences among males in Spain, Portugal, and the UK.In all three countries BMI, not WHR, accounted for the most variance in perceived attractiveness. WHR influenced attractiveness judgments for Spanish and Portugese, but not British men. However, even in the Spanish and Portugese samples WHR accounted for only about 18-19% of the variance, while BMI accounted for over 70% of the variance in perceived attractiveness. This paper also has a great summary of methodological issues with prior WHR studies (e.g., the use of two dimensional line drawing, failing to control for BMI). Cornelissen et al (2009) looked at patterns of British male gaze fixation during attractiveness judgments of pictures of women. Men tended to look at the upper abdomen and face, not the hip or pelvic area. The pattern of gaze fixations matched the way men evaluated the same pictures when estimating body fat, and did not match the way men evaluated WHR. Reading these papers suggests a lively debate in the literature about the universality of low WHR preference. I am not an expert in this area, and these examples don’t even scratch the surface, but they do indicate lack of consensus on the generality of the low WHR preference.

So, what does WHR even mean, evolutionarily speaking? Most people seem to argue that low WHR indicates a good balance of estrogen to other hormones, which is important for fertility. Fertility, undoubtedly, is essential to evolutionary fitness but 1) WHR isn’t going to be the only cue to fertility and 2) there are other important characteristics that may account for more variance in reproductive success in some situations (e.g., if the vast majority of women in a certain age range are fertile). Cashdan (2008) looked at actual average WHRs in a variety of cultures, mostly non-Western. She found that the average WHR was > .80 (remember, .70 is supposedly the magic number). Cashdan pointed out that androgens and cortisol both increase abdominal fat in women (increasing WHR). But, higher levels of these hormones are also associated with increased strength and stamina, which come in handy in less than optimal circumstances. She says: “Waist-to-hip ratio may indeed be a useful signal to men, then, but whether men prefer a WHR associated with lower or higher androgen/estrogen ratios (or value them equally) should depend on the degree to which they want their mates to be strong, tough, economically successful, and politically competitive” (p. 1104). This suggests that it’s possible to construct a perfectly reasonable evolutionary account for why men might prefer a high, rather than low, WHR (i.e., given a stressful environment where strength and stamina matter). The variables that dominate in a particular situation will likely depend on a number of specific environmental and cultural conditions. In other words, it’s complicated.

This story, unlike the one about low WHR preference, doesn’t seem to reflect our (modern, western) experience, so it’s less likely to catch the popular imagination. We don’t tend to think of male attraction based on female heartiness, but we also live in a particularly rich culture where we don’t spend a lot of time physically searching for / killing food or building shelters. So, here’s the psychologist’s fallacy again. Evolution is complicated and the features that confer fitness are necessarily dependent on context. This means that it’s not too difficult to think of a number of plausible evolutionary explanations for a particular phenomena. The preferred explanations are most likely going to be the ones that fit with our current experience, but this doesn’t make them better explanations.

via until a single soliton survives




Evolutionary Psychology Rap

(start at 09:00)

Too bad Gary S Becker was left out of the shout out. Rational discounting in response to environmental factors? It’s economics as well as evo psych!

Some awesome quotes:

  • 8:54 How do you know you’re not a persona? Huh?
  • 09:35 It’s an evolutionary strategy. You can’t magically escape from the habitat you was born in.
  • 10:00 If you’re thinkin / the criminal mind is vacant / you’re mistaken / This is calculated risk takin.
  • 10:15 Major discrepancy between the haves and have-nots / You wonder why the padlock on every cash box is smashed off?
  • 11:40 [Teen pregnancy] is such a tragedy / Apparently it’s also a reproductive strategy. / You can see people adjusting actively when circumstances change. It’s the same in different places and with different races.
  • 12:00 The bottom line is that inequity and life expectancy are the ultimate causes of crime / And the result of crime. / To me that’s true / The two combine together in a feedback loop.

 

I’ve got a request: if you grew up in a dangerous environment and can relate to the actual gangster lifestyle (not suburban mimics), please tell me what you think of this rap. Or, if you know someone who grew up living a hard life like this, would you show it to them and tell me their reaction?

(Source: )




Even the beneficiaries of hypertrophy have found it difficult to cope with extreme cultural change … they are sociobiologically equipped only for an earlier, simpler existence. Where the hunter-gatherer fills … one or two … roles out of … several available, his literate counterpart … must choose ten or more out of thousands, and replace one … with another….

Furthermore, each occupation—the physician, the judge, the teacher, the waitress—is played just so, regardless of the true workings of the mind behind the persona. [D]eviations … are interpreted … as a sign of mental incapacity…. Daily life is a compromised blend of posturing … and of varying degrees of self-revelation. Under these stressful conditions even the “true” self cannot be precisely defined….:

"…Self, then, is not … half-concealed behind events, but a changeable formula for managing … during them. Just as the current situation prescribes the official guise…so it provides where & how we will show through, the culture … prescribing what … we must believe ourselves to be….”

Little wonder that the identity crisis is a major source of modern neuroticism, and that the urban middle class aches for a return to a simpler existence.

E. O. Wilson (also quoting Erving Goffman), On Human Nature

Particularly the phrase “changeable formula” stands out to me. I think this means that our self-concept, seen as a function ƒ, takes the_environment as an input. (And that input has a nonzero derivative, i.e. it’s not a trivial input.)

Not only that; “the environment” isn’t limited to what_happened_in_our_early_years. We might feed that early_environment variable in as well, but in addition immediate conditions can change our self-concept. In equation form:

  • Self = ƒ (   ∫ early life,    present situation,   ...other stuff...  )