YOU WERE always in trouble as a child and were almost certainly treated harshly. You probably live on your own. You are probably the second child of a large family and grew up in a rural area with one strict parent and one who was often absent. You have some embarrassing, unacceptable, antisocial habits. If the above describes you, step forward - science needs you.

One hundred and seven people who answer this description have already given themselves up to scrutiny. And they are still calling from far and wide to join the growing family of disreputables and misfits.

The uncle who drinks too much, the sister who flirts too much, the cousin who loses too much at cards. All these and many others hovering on the outside edge of cosy family life answered the appeals placed in the national press and on breakfast television by Dr David Weeks, a clinical psychologist based in Edinburgh who is undertaking a research project into those who have been familially ostracised - more commonly known as the black sheep of the family. As co-author of a study entitled Eccentrics: The Scientific Investigation, he acknowledges a long-term professional weakness for people 'with uncommon behaviour as a way of life'.

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The expression 'black sheep' is frowned on these days by the politically correct, but Dr Weeks continues to use it for clarity of communication. The phrase has, in fact, no zoological basis. Black or white, lambs take their place in the flock without discrimination. Show any signs of being different in the human flock, however, and you risk getting branded right from the start.

Ostracism doesn't just happen in happy, smiling Weetabix families, it is every bit as common in families that are themselves on the fringe. 'There are some people in the study,' Dr Weeks says, 'who have grown up in dysfunctional families and they've been really decent people, but because they were not behaving in an antisocial way, their family distanced themselves from them and rejected them.

'One young woman from Birmingham came forward. She was brought up in a family of bank robbers which was also into dealing cocaine. As soon as she turned 16 they expected her to take on a kind of apprenticeship and help them in the family business. She eventually broke away and felt a lot better because she knew that what her family wanted her to do was wrong.'

The good egg in the rotten nest presents a very straightfoward case of someone not fitting in - the square peg in the crooked slot. The girl's evident 'goodness' or 'normality', however, does not disqualify her from being a black sheep. 'We are defining black sheep as anyone who has been ostracised by their family or who is seen as worthy of rejection, whether that is justifiable or not,' Dr Weeks explains, adding that part of the purpose of the study is to examine how social norms are formed and maintained.

Another woman phoned from New Zealand. She, an Australian, grew up in a family of fervently patriotic Aussies, and although she now says she occasionally felt 'the odd one out', there was no actual tension in her family until she had the temerity to fall in love with and marry someone from another country. The fact that that country was nearby New Zealand and her future husband spoke the same language and had a very similar cultural background made no odds. Her family have not spoken to her since. She is now a willing guinea pig in Dr Weeks's researches.

Initially, Dr Weeks explains, 'I wanted to establish whether or not the kind of behavioural differences which cause people to be ejected from their families are actually precursors of mental illness. With Huntington's chorea, for instance, there are stages where people become disinhibited and may do things which are considered immoral, unethical, or even criminal.' But there seems to be no substance to this hunch. More usually, the black sheep's 'differentness' is a thing of subtler hue.

Meanwhile, a profile is emerging. For the majority, their status as black sheep was evident in childhood, although for 21 per cent it developed in adolescence and for a further 20 per cent in early adulthood. Most of them are the second child and all had adoption or changeling fantasies which stayed with them all their lives. An unusually high number come from rural areas (52 per cent) and small towns (18 per cent).

But the most striking thing about them is that they are loners. 'They have the highest proportion of people living on their own of any patient group I have ever studied,' says Dr Weeks, who has published 30 papers on a wide variety of mental health topics and plans to publish his book about black sheep next year. Being treated as the black sheep can lead to 'a systematic erosion of self-assurance and an early undercutting of trust and certainty'. This, Dr Weeks says, can make such people ultra-sensitive to 'rejecting behaviour' - any signs of rejection and they are off. They are so used to being cast out on their own that in later life they choose to be alone. They don't think that they deserve anything different.

One such case is the London-based artist who 'has always revelled in being a stereotype anti-social person'. He has 'this kind of demonic, satanist view of himself. He uses a lot of devil imagery in his art which is obviously a metaphor for evil. No doubt given the right agent he could be really successful', says Dr Weeks, adding that this particular 'sheep' has used his creative side to 'divert him away from his perceived criminality, which he is always thinking about'.

Criminality is another uniting factor because, although only 15 per cent of black sheep have actual convictions, many more feel themselves drawn to not-strictly-legal activities. Often this is as a reaction to their loneliness, their 'outsider' status. Dr Weeks cites as evidence 'a woman who was first scapegoated by her family and then extricated herself from that family'. She became independent of them, set up her own business as a printer and met a man with whom she lived contentedly for most of her twenties.

'But then her boyfriend inexplicably committed suicide in the house where they were living and because she had no familial support, no family members who would be of any relevance to her at all, she had a very severe bereavement reaction and fell in with a bad crowd as a result.'

This bad crowd were synthesising heroin and had a sideline in armed robbery. But the girl felt she belonged with them and was eventually drawn into their activities and drove the gang's getaway car. She is now 29 and serving four years. 'She has accepted her guilt and is very remorseful. She contacted me from prison,' Dr Weeks explains.

Evidently being a black sheep can have dramatic results. But what of the causes? 'They have all got hard corporal punishment and rejecting behaviour from one parent in their backgrounds,' Dr Weeks says. 'This argues very strongly against physical punishment, and for that matter against emotional punishment as well. Such severity has unlooked-for consequences for the child's development, making them feel that they are outlaws.'

But is there any real harm in it? 'Oh yes, it does harm to individuals because it limits their mental and emotional development. And sometimes it does a great deal of harm to society because it stifles individual creativity. Parents are meant to facilitate mental development and creativity,' says Dr Weeks. 'But often creative, exploratory behaviour is seen as disruptive. So they quash it.'

But aren't there some people who are genuinely out of order and present themselves as black sheep because that is more romantic than admitting they are beyond the social pale? Dr Weeks denies that any of his subjects had romanticised their situation. 'On the other hand,' he adds, 'it is easier to think of yourself as a black sheep rather than as a hopeless drunk.'

Readers interested in participating in Dr Weeks's study can write to him c/o the 'Sunday Review', 40 City Road, London EC1Y 2DB

(Photograph omitted)