The governmental finger points firmly at split, joined or tangled up families as the source of children's emotional and behavioural problems in school. But this ignores the "beanpole" family. Figures for one-child families run at about 17 per cent in Britain, and there is evidence that children from these families often experience difficulties connected with their "only" status.
This is rarely recognised in the classroom. A new project in the Durham area has seen 12 teaching assistants undergo training to use some of their timetabled hours as one-to-one "listeners" with children who display emotional problems. Linda Smith, one of the listeners, was surprised that half the pupils in her first batch of referrals were only-children.
"Often we're not aware that a child has no siblings until something goes wrong," she says. "That's when we realise, and ask ourselves if this has a connection with the referral issue."
Most teachers say they would not have thought of only-children as having special problems. Yet the messages posted on the BeingAnOnly internet board show that hidden difficulties can last into adulthood.
Ann Richardson, the board's moderator and an experienced psychotherapist, says: "Growing up as an only child is no worse or better than having siblings but it is certainly different. Without the mirroring opportunities of lateral relationships in the family of origin, only-children can feel at a disadvantage."
Several of my clients - in another school where I work as counsellor - have been only-children whose difficulties could be understood in this light.
One boy in Year 5 lived alone with his mother, did most of the chores and was her confidante. In class, he looked stricken if the teacher spent time helping another child, misinterpreting her actions as rejection. A Y3 girl was a mini version of mother, always quoting her and referring to her - behaviour that would not serve her well in the future and was already losing her friends. A disruptive boy in Y6 attended eight sessions before expressing a feeling, such was his distrust of anyone knowing anything real about him.
So what are the main developmental and emotional difficulties that teachers need to be aware of?
Key to everything is the fact that children who have not been pushed aside by the arrival of a new baby may often still be at the egocentric stage.
The parents are part of their personal possessions. They have not learned to share, be ignored or even negotiate TV channels. Yet such children often dislike the intense monitoring they receive at home.
Bernice Sorensen has completed doctoral research on only-children. "Being the centre of attention and constantly observed leads to a lack of emotional space, a sense of suffocation and intrusion," she says.
Among my child clients, I have noticed that the reaction to such invasion is to guard feelings and thoughts with something approaching SAS secrecy.
This leads peers to assume that they are unfriendly, and to back off.
Worse, an only child's core relationships are mostly with adults, which means a very different power dynamic. It can result in an increased feeling of responsibility, and also a need to defer. This causes a diminished sense of separate identity: rebelling is unthinkable if parental support might be lost. As Ms Richardson says: "It's often difficult for the only child to truly separate from the parents. Some are still trying well into middle age."
Others, of course, will sail through life unaffected by their singular upbringing. Keith Hibbert, an educational psychologist who set up the Listeners project, says: "It does depend on pre-school and family experience. But only-children may be more vulnerable to peer-relationship problems and to an excess of parental expectation."
Both of these are knotty. Unless only-children develop a healthy self-identity, using parents and peers both as mirror and springboard, they may bury their real selves under a compliant outer shell. This bodes ill for teenage years, when rebellion is a sparky - if somewhat tiresome - sign of mental well-being.
* http:groups.yahoo.comgroupbeinganonly l www.beinganonly.com
Eleanor Patrick is a former teacher who now works as a counsellor in a primary school in County Durham. Any thoughts? Write to firstname.lastname@example.org
WAYS TO HELP A LONE CHILD
Egocentrism: Where an only child frequently seeks attention, find a quiet moment to reassure them that your relationship with them does not change when you have to attend to others. Undue secrecy: Use the non-threatening, brief contributions of circle time to help reserved only-children to become gradually more open about their feelings, and to experience acceptance by peers without intrusion.
Separation and identity: If an only child habitually defers to avoid conflict, look for opportunities through which they can talk about their own feelings. Encourage use of the words "..." and "me" to bolster what separate identity they have. If they dogmatically express "parental views", help them to hear alternatives without feeling criticised.
Socialising: Only-children often spend time alone. They become creative and imaginative. Look for ways to harness those assets - perhaps noticed in their writing or playing - to help them to socialise more and to form better relationships.