Romantic love and smart shopping make perfect match

The Pinker picture of love is a form of "smart shopping" and largely rational. Passionate emotions are not as irrational as we like to believe and claim. We are on the lookout for the best-looking, richest, smartest, funniest, kindest person who would settle for us.

"But your dreamboat is a needle in a haystack, and you may die single if you insist on waiting for him or her to show up. Staying single has costs, such as loneliness, childlessness and playing the dating game . . . At some point it pays to set up house with the best person you have found so far."

That may be the dominant currency of love but there is a place too for an irrational, capricious component that kicks in when Cupid strikes, he says. Also, we fall in love with the individual, not with the individual's qualities. We like the idea of finding a mate rated as a "10" but usually end up with someone of the same rating as ourselves. An intuitive process ensures we are "matched in mateability".

"Murmuring that your lover's looks, earning-power and IQ meet your minimal standards will probably kill the romantic mood, even though the statement is statistically true. The way to a person's heart is to declare the opposite - that you are in love because you can't help it."

When a US professor was recently listening to Pinker lecture on this aspect of love, he interjected, "now I know what I have been doing wrong all along!" But people don't want any suitor who wants them too badly or too early because of indications of desperation, or ardour too easy triggered.

He explained: "The contradiction of courtship - flaunt your desire while playing hard to get - comes from the two parts of romantic love: setting a minimal standard for candidates in the mate market, and capriciously committing body and soul to one of them."

If we were totally logical, like Star Trek's Mr Spock, we would instantly drop our number 7 if a number 8 moved in next door, or if Cindy Crawford or Tom Cruise became momentarily available, he said.

The emotional component of love, however, advertises that we are really committed. "Hence the stance, "I did not decide to fall in love with you. I cannot help it. Therefore, I won't decide to fall out of love with you.' And it makes the promise of courtship more credible if it looks like it wasn't rationally calculated."

Lovers and potential lovers may be relieved to hear that Pinker does not believe that we are preprogrammed for the mating game. We are much too sophisticated in behaviour - so many things going on in the mind at once. So it is impossible to predict with certainty what someone will do. People may be hopelessly in love but in there too is straight rationality, he believes: the product of evolutionary pre-determination of sets of thoughts and emotions - all working with calculation.

On individual attributes sought by the sexes as they go mate-shopping, the good news is that both men and women place a high premium on kindness and intelligence. Men, however, place a higher premium on looks and youth when in the marketplace compared with women. In contrast, women invest heavily in "status and earning power". Such preoccupations were not unique to the western world, he had concluded, but were universal among all of humankind.