Nature vs nurture

While a child's environment is important in shaping his moral compass, genes play a part too.

Ms von Auer said if children display deviant behaviour regularly or have the urge to commit violent or destructive acts, their pathology and motivations should be examined.

She said: 'There is a high probability the child is suffering from some psychological disorder such as an impulse control disorder like kleptomania (the need to steal or hoard) or a personality disorder, thus making it a nature factor.

'Nature and nurture are, however, intertwined and one can alleviate or exacerbate a bad situation. For example, a child may steal because his family cannot afford to buy him the toys he wants, but this may have to do with his circumstances or him wanting to fit in with his peers.'

Prof Wong said: 'Children from stable families, where parents set clear rules and boundaries and show their love, have a greater sense of morals.'

He agreed that both nature and nurture play a role, but he added: 'As to how influential nature is, it is a can of worms. Scientists cannot really pinpoint how one's genes influence one's morality, but we know they do.'

Although genetic make-up - and the propensity to be good - cannot be changed, psychiatrists and psychologists Mind Your Body spoke to emphasised the importance of a child's parents or guardians in shaping his moral compunctions by creating and reinforcing his moral framework.

Prof Wong said: 'Children grow and learn by observing. It is important for parents to decide on their family values and to live by them.

'This is most difficult as parents may not always be consistent or cannot walk the talk. Yet, a values system is the bedrock of a family.'

This article was first published in Mind Your Body, The Straits Times.