The best paragraph and a half I read yesterday

This is from William Saletan's New York Times review of Judith Harris's No Two Alike:

Ultimately, however, long-term behavior modification is at odds with itself. As our minds become subtler and our occupations less stable, short-term modifications suited to the situation at hand become more advantageous than permanent modifications. This is already happening, according to her theory. The reason parental influence doesn't control children's behavior outside the home is that they adjust to context. "Children are capable of generalizing — of learning something in one context and applying it in another — but they do not do it blindly," Harris observes. At home, where you're the younger sibling, you yield. At school, where you're one of the bigger kids, you don't. And unlike other animals, you can shuffle your self-classifications. In seconds, you can go from acting like a girl to acting like a child to acting like a New Yorker.

In short, the evolutionary logic that makes us different from one another will gradually make us different from ourselves, context by context. Personality — behavior that is "consistent across time and place," as one textbook puts it — will fade. We'll miss characters like Harris, the little woman from New Jersey who boasted of giving psychologists a "wedgie" and tried to solve the puzzle of human nature.

But is it true?  Cannot evolutionary pressures favor extreme constancy, for purposes of precommitting to transparency and attracting a better mate?

By the way, I'll give "best sentence of the day" honor to Daniel Akst: "Any benefit from shining the cleansing light of day on executive greed will probably be outweighed by the inflationary effect of additional disclosure, which will provide more ammunition for executives and consultants seeking to justify additional increases."