Here are three theories:

1. The contact hypothesis. As more men openly acknowledge that they are gay, it becomes harder for men who are not gay to discriminate against them. And as that group of openly gay men becomes more varied  including athletes, celebrities and soldiers  many of the old, derisive stereotypes lose their purchase. To that point, a Gallup poll released last May found that people who said they personally knew someone who was gay or lesbian were more likely to be accepting of gay men and lesbians in general and more supportive of their issues.

2. Men may be becoming more egalitarian in general. As Dr. Kimmel put it: “Men have gotten increasingly comfortable with the presence of, and relative equality of, ‘the other,’ and we’re becoming more accustomed to it. And most men are finding that it has not been a disaster.” The expanding sense of acceptance likely began with the feminist and civil rights movements and is now being extended to the gay rights movement. Dr. Kimmel continued, “The dire predictions for diversity have not only not come true, but, in fact, they’ve been proved the other way.”

3. Virulent homophobes are increasingly being exposed for engaging in homosexuality. Think Ted Haggard, the once fervent antigay preacher and former leader of the National Association of Evangelicals, and his male prostitute. (This week, Haggard announced that he was starting a new “inclusive” church open to “gay, straight, bi, tall, short,” but no same-sex marriages. Not “God’s ideal.” Sorry.) Or George Rekers, the founding member of the Family Research Council, and his rent boy/luggage handler. Last week, the council claimed that repealing “don’t ask, don’t tell” would lead to an explosion of “homosexual assaults” in which sleeping soldiers would be the victims of fondling and fellatio by gay predators. In fact, there is a growing body of research that supports the notion that homophobia in some men could be a reaction to their own homosexual impulses. Many heterosexual men see this, and they don’t want to be associated with it. It’s like being antigay is becoming the old gay. Not cool.

These sound plausible, but why aren’t women seeing the same enlightening effects as men? Professor Savin-Williams suggests that there may be a “ceiling effect,” that men are simply catching up to women, and there may be a level at which views top out. Interesting.