IT is the age-old debate – nature or nurture?

Now research from Edinburgh University has found that a person's genes, and not their upbringing or surroundings, are the key to determining how successful they will become.

A study of more than 800 sets of twins found genes play a greater role than their environment in forming characteristics such as self-control and decision-making ability as well as how sociable a person is.

The research team found that identical twins, whose DNA is exactly the same, were twice as likely to share traits compared with non-identical twins.

Psychologists say the findings are significant because the stronger the genetic link, the more likely it is that these character traits are carried through a family.

Professor Timothy Bates, of the University of Edinburgh's School of Philosophy, Psychology and Language Sciences, said: "Ever since the ancient Greeks, people have debated the nature of a good life and the nature of a virtuous life. Why do some people seem to manage their lives, have good relationships and cooperate to achieve their goals while others do not?

"Previously, the role of family and the environment around the home often dominated people's ideas about what affected psychological well-being.

"However, this work highlights a much more powerful influence from genetics."