Free will versus genetic destiny

Scientists are daily discovering genes involved in human behaviour, causing people to speculate about genetic determinism and freedom of choice. Yet while genes may influence behaviour they do not preclude free will, according to writer and scientist, Dr Matt Ridley.

Dr Ridley delivered a talk in Dublin last night on "Determinism, Free Will and the Human Genome". He was the guest of the Trinity College Genetical Society.

"I am trying to discuss how the discoveries in the genome will impact on the nature-versus-nurture debate," Dr Ridley said yesterday. "We need to get away from genes as puppet-masters and us as the puppets."

Two opposing poles in the development of human behaviour are represented by nature, that our genetic make-up dictates behaviour, and nurture, that our behaviour flows from our past experiences.

The human genome project, which has counted the 30,000 to 40,000 genes in the human genetic blueprint, has opened the way to the discovery of genes which influence behaviour, Dr Ridley said. "We are going to have a flood of genes for human behaviour over the next few years."

Before the discoveries coming from the genome project, researchers had believed there were 100,000 or more human genes, enough to dictate the conduct of human behaviour. Some researchers had already claimed that the much lower number of genes actually found proved that genetics could not be in control and that nuture was a more important behavioural influence.

Dr Ridley said, however, that our genetic code was "like a recipe, not a blueprint". The relatively small number of distinct genes still managed to produce a highly complex human result.

"Genes are a consequence as well as a cause of behaviour," he said. Genes were switched on and off in response to the surrounding environment, the person's own behaviour and even the behaviour of those around us.

"Once we see the genome as something that interacts with the environment rather than pulling the strings on a puppet, then we can begin to grope our way to a much more free-willed personality. We are a product of our background and our genes, but we are also capable of taking spontaneous decisions."

There was always going to be a "trade-off" of advantages and disadvantages in learning the significance of these genes, he said.

He took a generally positive view of these developments, however, saying: "I am an optimist, but a cautious optimist."

Dr Ridley is chairman of the International Centre for Life, a UK based centre which supports the public understanding of science. He is author of Genome: The Autobiography of a Species in 23 Chapters, and The Red Queen