Talk about your odd couples. Reagan pollster Richard Wirthlin and Harvard Prof. Carol Gilligan?

In the normal course of politics, you wouldn't find her book on moral development tucked between his computer printout sheets on voters. Nor would you expect to hear him quoting her ideas in the middle of statistics.

But this election year everyone is trying to chart the terrain of the gender gap, and Gilligan's book, "In a Different Voice," has become a most unusual pollside companion.

Wirthlin was among the first to note the significant gap between the way men and women feel about Reagan. He's also been out front warning the Republican Party that its support among women voters is perilously lower (10 to 12 points) than among men voters.

By now, the phrase "gender gap" has become a part of the common vocabulary of this campaign, and there's been a great deal of speculation about the reasons behind the "woman's vote." There are echoes everywhere among candidates of that old question, "What do women want?"

Some baffled analysts tell us that the women's vote isn't activated exclusively over peace issues, nor precisely over economic issues, nor exactly over women's rights issues. For want of a more exact phrase, many settled on one operative word: "fairness."

Enter Carol Gilligan. Her book describes the differences in development of men and women, especially differences in the evolution of their moral sensibilities. She suggests that men tend to see morality in terms of justice, while women tend to see it in terms of caring.

As Gilligan writes, "The moral imperative that emerges repeatedly in interviews with women is an injunction to care, a responsibility to discern and alleviate the 'real and recognizable trouble' of this world. For men, the moral imperative appears rather as an injunction to respect the rights of others and thus to protect from interference the rights to life and self-fulfillment."

This translates into politics in intriguing ways. For five decades, liberals have supported policies of caretaking, and a notion that we should use the government to protect people. Conservatives have supported individualism and the notion that we should protect people from the government.

Politics is never quite that simple. Conservatives, for example, can argue that a country that spends too much on social programs is ultimately a poor caretaker. Liberals can argue that the government can be better at protecting individual rights than at invading them.

Still, it's not surprising that when women begin to vote along the lines of their own values, there is a psychological tendency for them to vote along somewhat more liberal, more caretaking lines.

This inherent gap is bound to be exaggerated in this election. The Reagan administration has become a caricature of conservatism at its most careless.

Under its policies, the stock market and the unemployment rates have gone up in tandem. Money has been transferred from social programs to the military, from people to war. They have even tried to "deregulate" protection of the environment. It's also obvious to women that one sex, theirs, has suffered more in the Reagan era than has the other. So much for fairness.

Wirthlin likes to say that the gender gap has little to do with women's rights issues, like the ERA. Even Gilligan has pointed out that traditionally women find it difficult to put their own interests first. They are vulnerable to charges of "selfishness."

But she notes that along with the women's movement has come a change "enabling women to consider it moral to care not only for others but for themselves." The fairness issue, the caretaking issue, the women's rights issues are all coalescing in this election year. Women now include themselves in the list of people worthy of concern. It's likely that they will bring that complicated list to the polling booth.