In class today, we talked about the male and female differences in birth, and I found an interesting paper on the topic. It talks about a relationship between partnership-status and resultant offspring sex. The writer of the paper found a ratio which correlates to what we were speculating would be the percentage: when the mother had a spouse/partner, there was 51.5% male births. However, the percentage was 49.9% male births mothers who weren't living with a spouse or partner at conception. Anyways, while this paper doesn't exactly explain the genetics involved, it provides some support for the idea of conditions impacting the success of male vs. female babies.
]]>I found this article, which says that women are attracted to men who look like they would be good fathers. In this study, women thought that men who looked like they would be good fathers were generally less masculine. Doesn't this kind of contrast what we've been learning about mate selection, esp. the article we discussed today? How can women simultaneously prefer dominant, masculine men and less masculine men if resources and parental investment are both important? Does it have anything to do with the dual mating strategy?
]]>But, one has to wonder whether the cultural influence of sex-education is in part borne out of the same environmental conditions that would naturally select for early menarche. That is, in middle/upper income populations your future financial/resource environment in your 30s is more promising and stable than it is in your teens. Indeed, getting pregnant at an early age could be detrimental to your reproductive fitness, because it could be an obstacle to your establishing a career that would provide more favorable financial resources in your 30s.
In contrast, for lower income populations the promise of greater financial resources in one's 30s is considerably less certain. This would put evolutionary pressures to have children and thus menarche at an earlier age. There is some increased risk of pregnancy complications with increasing maternal age, but middle/upper income women (more so than lower SES peers) might be better able to offset such risks due to greater financial resources (e.g., improving diet and prenatal education).
So, the question is then posed again: is ealy menarche purely a cultural thing, or is it an observed cultural difference (between SES classes) that is borne out of an evolutionary pressure?
]]>In other news, I also stumbled on some information doing the above "research". Skulls were recently (since the printing of my reference books) uncovered in Africa indicating that modern humans existed as long ago as 160,000 ya. They do have a brow ridge, but more closely resemble modern, as opposed to archaic, homo sapiens. Some believe they should be put in a different subspecies: Homo sapiens idaltu. Still, this is further evidence that we evolved out of Africa and are not decendants of neandertals. click here for a pic.
]]>Also, what about difficulties reconciling the fact that we live in, and have evolved in, a physical world subject to rather strict physical laws? Does God choose to just operate within those laws, as Ken Miller suggests? Is there an issue with God creating laws that he can't break?
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]]>text messaging seems like the worse combination of attentional and peripheral resource demands
]]>I can't help but compare this to the reminiscence bump theories. Do we remember more info from the teens to mid-twenties because we have more time to encode them (as time is moving perceptually more slowly). Einstein would certainly have something to say about this, but I'm not smart enough to know what that might be.
Any thoughts?
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