by David P. Barash
There are a great many aspects of human anatomy and behavior that don’t make immediate evolutionary sense. A simple example is provided by male nipples, explained here. But there are even more inexplicable phenomena. For example, why is menstruation so copious? Other species menstruate, but they don’t release anywhere near as much blood as human females. And why is ovulation hidden? In many other species, ovulation is loudly announced so that males can make their best efforts. In human women, it seems that it is advantageous to keep ovulation secret. Perhaps this serves to fool the surrounding males that any of them could be the father, inducing them to refrain from harming the baby. Perhaps.
Or why is homosexuality so common? Why is it more common in males than in females? There are plenty of hypotheses to explain this — none of them terribly convincing. Perhaps it is a side effect of something more important, rather like the prevalence of sickle cell anemia. This is a side effect of a gene that grants resistance to malaria. One copy of the gene does the trick — but two copies of the gene triggers sickle cell anemia. Since most people end up with only one copy, the overall result is beneficial in malaria-infested regions. Perhaps homosexuality is based on something similar — except that there is no evidence of any gene that triggers homosexuality if two copies are present.
Another explanation arises from kin selection: if you can help your siblings prosper, then your genes are advanced in the gene pool. Therefore, behavior that is personally unbeneficial can still be genetically beneficial. For example, bees who sting an intruder to protect their colony will die, but in doing so they protect their own genes shared with other bees. Perhaps homosexuals sacrifice their personal reproductive advantage to provide additional services to their kin. It’s a nice idea — but the evidence doesn’t give much support.
The author addresses other oddities of human existence. Why do we make art? We pour a lot of effort into artistic endeavors, but what good does it do us? The hypothesis that I found most convincing was that women evaluate genetic fitness in men by evaluating both their intelligence and their honesty by evaluating their artistic skills. The intensity with which young adults engage in music certainly supports this. Young males are wont to make music, and young females certainly seem highly appreciative of such efforts. Moreover, males seem to be artistically more productive than females — does this indicate that art is akin to the feathers of the peacock?
And what about religion? Why is religious belief universal in human societies? Mr. Barash discusses the matter in great depth, and fails to come up with a convincing answer. I think that’s because he’s barking up the wrong tree. I have my own answer to the question: religion arose when two mental modules — social reasoning and nature reason — interacted with each other. That is, when people tried to understand natural phenomena, they applied their social reasoning module to explain nature in terms of powerful people (gods) who controlled natural phenomena, and sucking up to those gods would induce them to influence nature in ways beneficial to the supplicant. For more on this explanation, see this page.
Mr. Barash save the most difficult problem for last: consciousness. He flops all over the problem, relating all manner of possible explanations, but it is obvious from the vagueness of his discussion that he doesn’t have a good answer. There’s a reason why he can’t solve the problem: there’s no such thing as consciousness. Our notion of consciousness is actually just an extension of the old body-mind-soul concept from antiquity. We have a body, we have a mind, and we also have this “soul” thingamabob that “transcends” our dull, meaningless existence. In our more secular world, we have replaced the concept of an immortal soul with a mortal consciousness, but this consciousness still infuses us with some magical, mystical wonderfulness. Gosh, doesn’t knowing that you’re conscious make you feel better about your miserable existence?
There is something going on in the human mind that is unique to humans: personality modeling that is abstracted to the point that it permits both recursion and the creation of an entity we call “self” that is used in the internal mental model of personality to enhance one’s decisions. Read more about it here.
I enjoyed the book and certainly recommend it.
