A new candidate has emerged to claim responsibility for shaping personality. The usual suspects are, of course, genes (held responsible for everything from intelligence to optimism), upbringing, (one survey found that no fewer than 70 adult problems had been pinned on poor mothering), and, in popular circles, the stars (sexy Scorpios and chatty Geminis).

However, an article in the American Journal of Pre and Perinatal Psychology, suggests that there is such a thing as a Caesarean personality. Children who do not go through labour, claims its author, the American physicist Dr Jane English, have a number of distinctive characteristics as a result.

She has developed a special interest in Caesarean births and is a resource centre for individuals and professionals interested in the subject.

'The differences are very subtle but they come out most clearly in relationships,' she says. 'Caesarean babies as they grow up tend to be both dependent and impatient. They don't know the rhythm of getting to know someone and sustaining a relationship.

'They have a feeling of not really being attached to any person or idea. They are kind of free floating,' Moments that strongly distinguish Caesarean birth from vaginal birth, she says, include feelings of shock and rape when the mother's belly is cut and the terror, loss and 'explosive dying' that accompanies being pulled free of the uterus.

So far the theory is based on anecdotal evidence from those who, like Dr English, have 'regressed' via therapy to the moment of their birth and claim to have re-experienced it. Recent court battles in the US between alleged incest survivors and their parents have raised serious doubts about the reliability of memories uncovered during therapy - the so called 'false memory syndrome'. If people can imagine events that supposedly happened when they were eight or 10, how much more likely is it that birth memories are imagined, too?

False memories aside, though, it is generally accepted that traumatic events in childhood can have a lasting effect and it is not difficult to imagine the shock of being plucked without warning from the dark, watery safety of the womb. The question is, then, how involved are babies in their birth, and how aware of it are they?

Sheila Kitzinger, a baby expert and author, is uncertain. 'We know now that babies are much more active partners in vaginal birth than obstetricians used to think. All that pressure on their head and feet from the uterus stimulates reflexes that help them to wriggle their way out and they get a huge boost of adrenaline-like chemicals in their blood.

'Caesareean babies certainly miss all that - but I don't know what the effect is or how you'd measure it.' And she dismisses the idea that it might have a major effect on personality.

'The social context and the relationship with the parents far outweigh anything else. Also, it's dangerous to try to predict a baby's behaviour from the sort of birth it has had. If you look for a certain sort of behaviour you can always find it.'

The crucial assumption of the Caesarean personality theory is that birth is remembered. Professor Peter Hopper of Queen's University, Belfast, recently reported that a foetus can remember much more than is generally thought. But he doesn't believe this offers a firm footing for the theory. 'It's true that experiences like songs heard in the womb are recognised after birth, but the memory fades within a month,' he says.

He has a further objection. 'There is the assumption that the normal process of birth is valuable but it can vary enormously - some are out in half an hour, some in 24 hours. If there was an effect you'd expect to see a personality difference there as well.'

All this puts the Caesarean personality theory on the level of horoscopes. But the idea made some sense to at least one expert.

'There's been a three-fold increase in Caesareans in the last 20 years,' said Gina Lowdon, who runs an offshoot of the National Childbirth Trust called the Vaginal Birth After Caesarean group. 'We don't really know if they have a long-term effect or not. Either way, it might be a good idea if Caesarean babies were given some massage after birth to simulate the contractions they missed.'

For the moment attention remains concentrated on the well-being of the Caesarean mother. Without formal research the notion of the Caesarean personality seems destined to remain a convenient excuse for explaining away life's normal parcel of difficulties.

(Photograph omitted)