The moral gene

The proposal, if true, would have far-reaching consequences. It implies that parents and teachers are not teaching children the rules of correct behaviour from scratch but are, at best, giving shape to an innate behaviour. And it suggests that religions are not the source of moral codes but, rather, social enforcers of instinctive moral behaviour.

Both atheists and people belonging to a wide range of faiths make the same moral judgements, Hauser writes, implying 8220;the system that unconsciously generates moral judgments is immune to religious doctrine.8221; Hauser argues the moral grammar operates in much the same way as the universal grammar proposed by the linguist Noam Chomsky as the innate neural machinery for language. The universal grammar is a system of rules for generating syntax and vocabulary but does not specify any language. That is supplied by the culture in which a child grows up.

The moral grammar too, in Hauser8217;s view, is a system for generating moral behaviour and not a list of specific rules. It constrains human behaviour so tightly that many rules are in fact the same or very similar in every society8212;do as you would be done by; care for children and the weak; don8217;t kill; avoid adultery and incest; don8217;t cheat, steal or lie.

Matters of right and wrong have long been the province of moral philosophers and ethicists. Hauser8217;s proposal is an attempt to claim the subject for science, in particular for evolutionary biology. The moral grammar evolved, he believes, because restraints on behaviour are required for social living and have been favoured by natural selection because of their survival value.

Much of the present evidence for the moral grammar is indirect. Some of it comes from psychological tests of children, showing that they have an innate sense of fairness that starts to unfold at age 4. Some comes from ingenious dilemmas devised to show a subconscious moral judgment generator at work. These are known by the moral philosophers who developed them as 8220;trolley problems8221;.

Suppose you are standing by a railroad track. Ahead, in a deep cutting from which no escape is possible, five people are walking on the track. You hear a train approaching. Beside you is a lever with which you can switch the train to a sidetrack. One person is walking on the sidetrack. Is it OK to pull the lever and save the five people, though one will die? Most people say it is.

Assume now you are on a bridge overlooking the track. Ahead, five people on the track are at risk. You can save them by throwing down a heavy object into the path of the approaching train. One is available beside you, in the form of a fat man. Is it OK to push him to save the five? Most people say no, although lives saved and lost are the same as in the first problem.

Why does the moral grammar generate such different judgments in apparently similar situations? It makes a distinction, Hauser writes, between a foreseen harm the train killing the person on the track and an intended harm throwing the person in front of the train, despite the fact that the consequences are the same in either case. It also rates killing an animal as more acceptable than killing a person.

8212;NICHOLAS WADE / New York Times