The sexual revolution has come a long way: now men are judged just as harshly as women for having "too much" casual sex.

It is increasingly a "level playing field," said researcher Rachel Allison of the University of Illinois, who looked at the survey responses of more than 19,000 college students from 22 different US schools.

Based on their responses to questions, including "If (wo)men hook up or have sex with lots of people, I respect them less," the study found nearly half (48%) of students were "egalitarian conservatives" - meaning, equal opportunity disapprovers.

Women were more likely than men to lose respect for promiscuous peers of either gender: 54% of female respondents, as compared to 35% of males.

But only a quarter of the men hold the traditional double standard of losing respect for sexually liberal women but not men.

About 27% of respondents were "egalitarian libertarians" - they don't care how much a man or a woman hooks up.

Religion and sexual orientation factored into the responses, the study found.

Buddhist, Jewish or "non-affiliated" students were less disapproving than Catholic students, and those who identify themselves as "non-heterosexual" were less disapproving than heterosexual students.

The findings were to be presented at the annual meeting of the American Sociological Association, which began Friday in Denver.