[U]Why Gender Matters[/U} Anyone read?

[Dancing David]

I heard the author of Why Gender Matters , Leonard S x MD, PHD and I think that he had some cogent points about the differences between male and female humans. And then at one point ghe totaly steped off the ddep end. First he started talking about potential evolutionary strategies for the difference between males and females and then he began just no stop anecdotes from primate research he talked about things like "male monkeys play with trucks and female monkeys play with dolls' and at no point did he cite more than one study for this evidence. I haven't read the book but I will try to find it at the library, it really bothered me that he went a cited anecdotal studies to support his claims.

The real problem that I had with his evolutionary stuff was this, males have higher levels of testosterone than females, what gender differences can be atributed to a male being an androgenated female and which ones could actual be based upon gender roles for evolutionary benefit? I think that the first is the simpler explanation and less deterministic.

 

[Roboramma]

The real problem that I had with his evolutionary stuff was this, males have higher levels of testosterone than females, what gender differences can be attributed to a male being an androgenated female and which ones could actual be based upon gender roles for evolutionary benefit? I think that the first is the simpler explanation and less deterministic.

Except that the ways in which testosterone affects a developing male are susceptible to natural selection. So is the amount of testosterone that the typical male's physiology has.

Of course, it's true that if we look at any particular difference between the sexes, we can't know if that is just a side effect of testosterone that wasn't selected against strongly enough to lower the amount of testosterone in males, (if we're talking about a male attribute, just to keep things simple), or if a gene just hasn't had enough time to come up to counter that affect, or if that was an effect that was itself selected for.
There may be ways to determine that, but you're right that we can't know that every feature is adaptive before we actually try to find out.

But anyway, I'm just saying that just because there is a physiological explanation for a characteristic (in this case say increased muscle growth due to higher levels of testosterone) doesn't mean that there aren't also evolutionary explanations as well.

For instance, I'm sure that new genes, by changing the balances of other hormones, or the structure of the muscle cells, men with a high level of testosterone could also have similar muscle growth to women, if such were to be selected for.

 

[drkitten]

Except that the ways in which testosterone affects a developing male are susceptible to natural selection. So is the amount of testosterone that the typical male's physiology has.

Of course, it's true that if we look at any particular difference between the sexes, we can't know if that is just a side effect of testosterone that wasn't selected against strongly enough to lower the amount of testosterone in males, (if we're talking about a male attribute, just to keep things simple), or if a gene just hasn't had enough time to come up to counter that affect, or if that was an effect that was itself selected for.
There may be ways to determine that, but you're right that we can't know that every feature is adaptive before we actually try to find out.

In some cases, we can come up with some educated guesses based on other animals. Just as an example -- human males are larger on average than human females. But if you look across all different species of primates, there is a large variation in the ratio of male size to female size. (And in particular, I can't think of a primate species offhand where females are larger than males.) Furthermore, there are some pretty strong correlations between forms of mating behavior -- particularly a tendency to polygamy -- and large males (relative to females).

This suggests (to me) that the larger size of human males has been selected for, and that it's not simply a side effect of testosterone. If it were just a side effect, these variances wouldn't exist, because all primates would respond the same way.