In a nationwide poll, Princeton University's Office of Population Research asked people what they would do if they could choose the sex of their firstborn. It found that 45 percent said they would like to have boys and only 20 percent would choose to have girls. Not surprising, you say. Hold on a minute. All the people surveyed were women.

Not only that, but the results of the recently released survey were no different in 1975 than in 1970, and no different, either, for women who were described on the basis of other questions as "radical feminists." Across the board, American women would rather their first child be a boy--a choice that says quite a bit about how women themselves see their own lives. They are saying that sex still matters--maybe matters more now than ever.

But just why women choose boys over girls for the firstborn remains an official mystery. Princeton failed to ask them. Instead, it was mostly concerned with the demographic implications of the survey--namely, that if couples had just one child and could choose its sex (a likely scientific development) men would soon outnumber women. And even if couples had more than one child and the second one was always a girl (the clear preference for the second child), society would still be changed. Firstborn children are usually more aggressive and success-oriented.

Still, it is interesting to speculate on the reasons for these findings. It could be that the women were trying to please their husbands. Or it might be, as some women have suggested, that the women queried had vivid memories of their own relationships with their mothers, especially the scorched-earth warfare of the teen-age years. Fathers and sons have their troubles, but almost nothing on earth compares to what mothers and daughters do to one another. There is nothing quite like it in the entire animal kingdom.

Some women thought that maybe the findings reflected the Freudian mine field that sometimes characterizes the relationship between fathers and daughters--the flirting, the charming and, of course, the competition between mother and daughter for the attention and affection of the father.

But whatever the reason, the survey says something in and of itself. It implies that women do not like something about being women. Since anyone can recognize that the firstborn may turn out to be also the last born, there is a kind of message in the survey that says that when the chips are down, that when only one child might be born, it should be a boy.

In some ways, the survey might be comparable to the classic experiment performed by Kenneth Clark, the psychologist, in which he showed that when black girls were given a choice between white dolls and black dolls, they invariably chose white ones. The conclusion was obvious: Years of discrimination and bigotry had instilled in black girls a certain lack of self-esteem and it was this finding that helped the Supreme Court to conclude in 1954 that separate but equal racially segregated education was inherently not equal. When it comes to women, one brush with an intense antifeminist is enough to convince anyone that they, too, believe in their own inferiority.

But a more obvious explanation is that even after all these years of the women's movement and vast advances in women's rights, it is the judgment of women themselves that it is still a lot easier to be a man. The reasons are bluntly pragmatic--men are allowed to do more, get better jobs, make more money, don't usually raise children and don't suffer the sort of career-vs.-parenting conflicts that women do.

In fact, it is not surprising that the survey results did not change any from 1970 to 1975 or that "radical feminists" responded the same as other women. The survey reflects the reality of their lives, not what they think of themselves. If anything, it might now be harder to be a woman than it's ever been. A survey taken today might show similar results.

Whatever the reason, the survey seems to refute the argument that the women's movement has won its battle and that the great era of sexual equality has dawned. Women themselves seem to know better. All kinds of statistics can be marshaled to prove that women and men are still not equal, but none can be as poignant as the results of the Princeton survey.