Kanazawa and Still claim, in all likelihood correctly, that females are the choosers in all species where they invest more parentally than males. In these species it is the male that is the object of sexual attraction. However, it is well known that in humans this pattern has been reversed so that it is the female rather than the male who is the primary object of sexual attraction. For this reason, Kanazawa and Still's attempt to draw a parallel between humans and other animals in the mode of mate choice does not succeed.What has Sanderson been smoking? The male is the primary object of sexual attraction in most species? Surely when the female gets to chose and the male must display, that means the female is the sex object. Being the selective sex equals being the object of sexual attraction as I understand it. Peahens (say) may look drab to us, but it is they who are the attractive ones. They are the sexy sex. The peacock isn't attractive; he is desperately trying to attract females with a pathetic and costly display. Most males are unworthy of most females and it would be ludicrous to call an average peacock who may well fail to attract any female at all the primary object of sexual attraction while every female is desirable by default. This has not been "reversed" in humans. It is precisely the same. Some women are more desirable than others of course and able to get men of higher status, and they do things like boob jobs and wear makeup to enhance their attractiveness which peahens don't bother with, but fundamentally it is the same. If the peacock's display makes him a sex object, then men must be termed sex objects by virtue of our desperate and largely futile attempts to seduce women, and clearly that is preposterous.
We all know that women are sex objects (and the bodies of men are worthless, in other words sex is a female resource, universally understood as something women have and men want as Baumeister makes abundantly clear), and I believe that is the case in other species as well where the female invests more parentally. The only true male sex objects (besides homosexuals, of course) are found in the few species where the male invests more in parenting, e.g. the bird Centropus grillii, where the males care for the young while the females spend a large proportion of their time calling from conspicuous perches. It would be nice to be a sex object, but the downside is the parenting burden. You have to work hard either way, but the choosy sex has the bonus of being sexy -- they have intrinsic value unlike men and an extra unlimited resource at their disposal -- so in the aggregate women have it easier. Females of most species are also virtually assured reproductive success, but on the other hand men can succeed spectacularly when they do succeed, like Djengis Khan.
By the way I found Sanderson's explanation of monogamy somewhat compelling. Male choice may in fact have a hand in polygyny -- not everything is completely driven by women.
Baumeister, R.F. & Vohs, K.D. (2004). "Sexual Economics: Sex as Female Resource for Exchange in Heterosexual Interactions." Personality and Social Psychology Review, 8, 339-363.
Wolfgang Goymann, Andrea Wittenzellner & John C. Wingfield. "Competing Females and Caring Males. Polyandry and Sex-Role Reversal in African Black Coucals, Centropus grillii." Ethology, Volume 110 Issue 10, pp. 807 - 823.
Sanderson, Stephen K. "Explaining Monogamy and Polygyny in Human Societies: Comment on Kanazawa and Still." Social Forces, Volume 80, Number 1, September 2001, pp. 329-335.