Counting the kisses

Tony Honoré

  • Sex and Reason by Richard Posner
    Harvard, 458 pp, £23.95, May 1992, ISBN 0 674 80279 9

Richard Posner, Federal judge, prolific writer and teacher, is the leading figure in the American ‘law and economics’ movement. That movement has pioneered a new way of explaining Anglo-American law and showing how it could be improved. Its method is to analyse topics – for example, the law of compensation for accidents – in economic terms. So analysed, law for the most part emerges as a set of rules serving rational ends. In accident law, for instance, legal rules are said to achieve the sort of result that would emerge from negotiations at arms’ length between those who cause and those who suffer accidents. But such negotiations would be costly and time-consuming, and accident law spares the parties this cost.

Underlying the analysis is a sort of legal Darwinism. The laws that survive are those that best satisfy preferences because they unconsciously imitate the market. There are of course exceptions to this happy operation of the hidden hand. Pressure groups sometimes distort the rules and there can be historical hangovers. But on the whole whatever is economically optimal is the law. When it is not, economic analysis brings this out and points the way to reform.

Posner has now applied this framework to sex and its regulation in a book as bold and ambitious as anything he has written. It analyses sex as a morally indifferent topic like eating. We are to understand the factors that influence sexual behaviour and then choose dispassionately the best policy for regulating it, just as legislators would choose the best agricultural policy, keeping in mind the warning: ‘in sex as in other areas of life beware of government regulation.’ The first part of the book outlines the history of sexual behaviour along with theories intended to explain it and laws intended to curb it. The second, the core of the work, sets out Posner’s bio-economic explanation of sexuality. The third, more concerned with social and legal policy, is written from a libertarian point of view that owes much to J.S. Mill. It is concerned with the regulation of marriage, contraception, abortion, homosexuality, pornography, rape and non-sexual reproduction. It also traces how the US courts, disregarding market principles, first embraced and then withdrew from the sexual revolution of the Sixties and Seventies. Throughout, Posner summarises empirical research and gives weight to its findings.

He argues that though there are fixed aspects of sexuality that cannot be altered, it is more responsive, by and large, to (non-monetary) costs and benefits than is commonly supposed. The fixed aspects he sees as mainly two. Men have on the whole a greater sex drive than women. All but a few people have a fixed preference either for the other sex or for their own, though if the cost of pursuing that preference is too great they look for a substitute. These fixed points are better explained by (socio )biology than by environment or social pressures. Hence the theory is not just economic but bio-economic. The male bio-strategy is to spread male genes as widely as possible, the female strategy to mate with the male fittest to father and most likely to protect her offspring until maturity. This picture certainly has some plausibility. Its weakness is that no one has so far identified the genes that predispose us to gene-preserving behaviour.

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