The roots of personality

If a young man committed a serious crime in pre-colonial China his parents were liable to be executed with him, on the grounds that they were also to blame. This logic is reappearing in contemporary social policy: parents are responsible for shaping their children's behaviour; delinquency is rising; parents must be doing something wrong. If a few were made an example of, the rest might mend their ways and bring up their children properly. But do even the best of parents have that much control?

One of the best kept secrets of psychological research over the last ten years is the growing volume of work which suggests that parents do not have nearly as much influence over their children as we both hope and fear they have. Part of this evidence comes from the controversial discipline of behavioural genetics. Popular coverage of this has concentrated on the sensational (and false) notion of a gene for alcoholism, homosexuality and so on. But a decade of research by Robert Plomin and others at the Institute of Psychiatry in London, together with studies of twins in the US, suggests that about half of our adult personality is the result of our genes. If identical twins are separated at birth and brought up in different households, their adult personalities will be as much alike as if they had been brought up together. Many parents' actions, which you would imagine must make a difference, do not.

Take eating: what could be more obvious than the idea that children whose parents both overeat will grow up to do the same? But this is not the case. Adopted children, who do not share the overeating parents' genes, do not copy their behaviour. The same applies to watching television. Adopted children in a household which watches a lot of television will not sit glued to the box, unless watching television is something their biological parents also like to do. Even attitudes to, say, hanging or jazz, apparently prime candidates for parental influence, turn out to have a strong genetic component.



Public debates about the effect on children of corporal punishment, divorce or violence on television, scarcely mention a fact which every parent of more than one child knows-that different children respond differently to the same broad influences. This is because developmental psychology has resolutely ignored genetics for the past 50 years.

genes and personaLITY

One researcher who has tried to measure personality in very young children and to test its effect is Harvard psychologist Jerome Kagan. He has identified two basic types-inhibited and uninhibited-and has started to tease out some of the physiological bases of children's behaviour.

An inhibited child is likely to show a fear of strangers at only a few months, to be quite restless and to have high levels of the brain chemical norepinephrine. An uninhibited child smiles readily, is calmer and has a different brain chemistry. Each type responds differently to discipline and is likely to have a different career pattern.

This is a very basic division, found not only in humans but in all mammals. But Kagan suggests that it is just the beginning. He believes that there may be several dozen different temperaments with distinct patterns of behaviour. If this turns out to be true, it will make one "best way" to bring up children meaningless. A sharp rebuke which instills shame in one child will simply make another angry.

There are many reasons why the genetic element in the study of personality has been unpopular-from liberal commitment to a meritocratic equal start, to the shadow of Nazi eugenics. For most of this century, educators and social commentators have placed responsibility for a child's development on his or her environment, especially on the parents. Freud and the behaviourists agree on this point (although they disagree on just about everything else).

These two schools' wilder assertions now seem rather old-fashioned as genetic influence becomes more accepted in clinical circles. Until the 1970s, for instance, psychoanalysts claimed that autistic children were the result of "refrigerator mothers"-women who were so emotionally distant that their children never learned to form close relationships. Now autism is generally accepted to have a strong genetic basis. Similarly, hardly anyone now believes, with the behaviourists, that the reason why some children have speech problems is that their parents failed to talk to them enough. The development of language is acknowledged to have a large genetic component.

For those who were brought up on behavioural-psychoanalytical assumptions, merely acknowledging that genes play a significant part in children's development is a big step. But it is only the beginning.

the "dark matter" of development

Mountains of books and articles describe how authoritarian and over-protective parents can make a child timid, while the permissive approach produces anxious children. Then there are the biographies of the famous. Each has a chapter attributing success to overcoming the handicap of awful parents, or to the unwavering support of loving ones. But this is not what behavioural geneticists have found.

None of these books actually makes allowance for the basic fact that children share 50 per cent of their parents' genes. It is not very useful to report that children of parents who have bad eating habits or suffer from depression tend to do the same. When the genetic element is removed, as in adoption studies, the link usually disappears. But genes do not make a straitjacket, they provide the raw material which a child's environment then fashions into different finished material.

But what is it that, in turn, shapes the child's environment if it is not the parents? Borrowing an analogy from astrophysics, this is the missing "dark matter" of developmental psychology. In an attempt to solve the mystery, Plomin developed the idea of "non-shared home environments." If the effect of parents is not the answer, maybe the crucial influence is the micro-environment unique to each child.

Every child arrives at a different time in a family's history. When the first one is born the parents may be struggling; by the time the last one arrives they may be more relaxed. Each child will experience specific events-an illness, an accident, a particularly good or bad teacher. It is this "non-shared home environment," Plomin says, which is crucial in shaping the child's personality. He also points out that children's differing genetic makeup means that they vary from birth in all sorts of ways-in how attractive they are, how assertive, how likeable-and that this directly affects the way adults treat them. The nurture view sees aggressive treatment producing an aggressive child-but it may be that an aggressive child produces aggressive behaviour in the adult.

Another micro-environment factor which has recently become fashionable is birth order. Depending on whether you are the first or last born you will experience your family differently-a classic example of a non-shared home environment. Studies show that up to 80 per cent of parents, for instance, admit to loving a younger child more than an older one. If non-shared home environments do shape personality, birth order should have a measurable effect-there should be consistent differences between first- and second-borns. But there are none. Claims are regularly made for birth order effects, but they do not stand up to close scrutiny.

Recently, a new attempt to pinpoint the "dark matter" has been made by the American psychologist Judith Harris. In the journal Psychological Review, she suggests that adult character is not shaped by a claustrophobic, Oedipal drama played out between ourselves and our parents, but by how we get on with other children in the neighbourhood. Psychologists often marvel that children turn out all right despite great differences in the way parents treat them. According to Harris, this is because the lasting influence comes not from the parents, but from a group found everywhere with little variation-the children's playgroup.

This is heresy, and at first sight seems absurd. But combining evidence from areas of psychological research not usually considered in development debates, Harris makes a powerful case for group socialisation (GS) theory. She starts from the fact that we learn a particular behaviour in a specific context. (Everyone knows the person who is a bully in the office and a doormat at home.)

The home is just one of several environments in which children have to learn how to behave. So you can affect children's behaviour in the way they behave at home, but this does not necessarily transfer to other situations. "This makes evolutionary sense," says Harris. "The parental home is not where children are likely to spend their future. They are already genetically similar to their parents. Adopting all their habits as well would give them much less flexibility for adapting to changing conditions in the outside world."

Those who subscribe to nurture theory concentrate on "dyadic interactions"- relationships between two people, typically mother and baby. But learning how to behave with one person does not tell you much about how to behave with someone else quite different-your father, for instance. Far more powerful in shaping behaviour, according to GS theory, is the effect of the group.

Humans are social animals. Over millions of years of evolution we have developed mechanisms for getting on with others in the group, as well as competing for status and mates. This is the second area of research which Harris brings to the problem of "dark matter": the psychology of the group. We know that groups instill a strong drive to conform. Parents know what it is like when a previously easy-going child suddenly refuses to be seen in anything but the tee shirt which has been declared "in" by the group.

An important piece of evidence suggesting that the children's group has a greater effect than the home comes from the study of language. One of Harris's supporters is the language researcher Steven Pinker, author of The Language Instinct: "Certainly in the area of language we find two striking effects in favour of Harris's idea: First, children of immigrants pick up the accent of their peers-not their parents, not their teacher, not television announcers. Second, children in a group will quickly develop their own language if they don't start out with one."

Even more fundamental to our personality and sense of identity is gender. From the nurture viewpoint, gender roles are a key area where parents have an influence-the distant father, the critical mother and a variety of other parenting styles can, it is claimed, significantly affect the development of a child's sexual identity. But evidence to the contrary is strong.

John Archer of the University of Central Lancashire, another supporter of Harris, has been studying how gender differences develop. "We have now had about 20 years of a concerted attempt by a whole class of parents to raise boys and girls in much the same way," he says. "Yet, as every school and every parent knows, boys and girls automatically split themselves into single sex groups from an early age." Once in these groups, they develop quite distinct patterns of behaviour. It is these, rather than their parents', which children pick up. Gender roles, like language, seem to be under the control of the group.

group influence on children

One childrearing approach which empha-sises the power of the group over that of the parents is the British public school system. "Whole generations of upper class British males had a childhood that involved distant parents, an authoritarian father, nannies and a brutal boarding school," says Harris. "The results support the GS view. Although the fathers had little or nothing to do with their sons, the boys turned out very much like the fathers and not at all like the nannies."

Children do share their parents' beliefs-not because of the parents' careful upbringing, but because of the way that the parent's group affects the children's group. You can see the effect clearly when the parents of a child do not share the values of the parents of the rest of the children in the group. This often occurs with immigrants: GS theory predicts that the children will adopt the values of the group, not those of the parent.

There is nothing new in the idea that peer pressure influences children. What is original about GS theory is its claim that the long-term influence is much greater than that of the home and that it starts much earlier than has generally been acknowledged.

GS theory also offers a fresh perspective on the apparently harmful effects of divorce. Harris points out that divorce often has a turbulent impact on a child's relationship with his or her peer group: "Many of them move house, which means they lose their place in the local hierarchy and have to work to be accepted into a new group. They may well move to a poorer neighbourhood and so have to deal with a group with different norms. As a result of these changes, the child's behaviour changes, usually for the worse."

So does it matter how parents behave towards their children? "If you are cruel or indifferent it won't ruin your child's personality," says Harris, "but it can certainly ruin your relationship with him or her. If you want your kids to like you when they are grown up, you'd better be nice to them now."

GS theory does not deny that the way parents behave towards their kids affects the way they behave at home. But learned behaviour is tied to the situation it was learned in. Just because your kids whine and bicker at home does not mean that they will do so in the playground: the standards of acceptable behaviour, as well as the punishments and rewards, are quite different. Parents are often surprised when they talk to their child's teacher: "Is she talking about my child?"

Galling as these findings may be to parents with an account at the Early Learning Centre, they could lead to a less anxious approach to childraising and a greater appreciation of the role played by schools. It certainly implies that blaming individual parents is a waste of time.