Focus: Is there a little monster in your house?: Sibling rivalry can flare into bullying and violence. Beverley Hopwood and Monique Roffey unmask a problem. Below, family members tell their stories

ELEVEN-YEAR-OLD Jessica is terrified of the bully lying in wait. Every day she is baited, kicked and slapped. Her only solution, she reckons, is to run away from home. For Jessica's 14-year-old tormentor is her sister.

Jessica is one of the desperate children who have rung ChildLine in recent months, targets of sibling bullying and abuse. Of the calls the charity receives about brothers and sisters, 15 per cent involve serious violence.

Scotland Yard's child protection unit has 318 cases of sibling violence on its 1991 file, including two murders and 30 cases of GBH. But these are only the most extreme cases. It says nothing of the countless children for whom sibling bullying may not lead to a tragedy but certainly leaves bruised minds if not bodies.

Inquiries within our circle of friends alone threw up a surprising number of adults who had suffered at the hands of a brother or sister: knives and even airguns had been used.

In the United States, where the problem has been slowly gaining recognition since the late Seventies, research has indicated that sibling violence - biting, kicking, punching and attacks with implements - is the most common form of domestic violence. Three recent studies reveal that though aggression is more likely to erupt between same-sex siblings, boys and girls are equally aggressive. Other research suggests that siblings do not often 'tell' on each other.

Dr Sue Edwards, a domestic violence expert at the University of Buckingham, believes that although we do not hear about abusive brothers and sisters, there are plenty of them. 'I think we can say it's a deep, dark secret,' she says. 'I don't know how we would know about it anyway, because what voice does a child really have? Where would a sibling go? How could a 13-year-old girl go to the police and say, 'My 15-year-old sister is punching me'?'

Dr Edwards believes that the problem is likely to be masked because children are seen as equals. Aggression is usually seen as no more than 'kids will be kids' fisticuffs, or good old-fashioned sibling rivalry. 'It's been internalised in our language,' she says, 'mothers saying 'it's six of one and half a dozen of another' and 'I'll knock your heads together'. Fighting is seen as almost an innocent form of development - yet where are the boundaries?'

Childcare experts seem to agree that sibling rivalry reaches danger point when a pecking order takes root. Fighting moves beyond the two-way aggression of normal sibling squabbles and one child is dominant. One child might break up the other's possessions, even turn on the other's personal pet.

Dr Penelope Leach, a child development expert, believes parents must rid themselves of the 'blood is thicker than water' notion which says that whatever happens within the family must be all right.

'There's this great desire to assume, 'Yes, it's a love/hate relationship but the love's always stronger',' she says. 'That's probably usually true, but you have to be alert to the possibility that it isn't true. Parents have to ask themselves, 'Would this behaviour be acceptable if it were school friends rather than siblings?' '

Dr Leach cites an example of one family in which three children, all now successful professionals, lived under the tyranny of the eldest brother. 'Mostly it was extreme bossiness and power play and they were very frightened of him and have never forgiven or forgotten. It was a real factor in what they felt about going home and desperately not wanting their parents to go out in the evening. The youngest girl grew up with extremely low self-esteem, feeling fat and stupid, and she puts a great deal of that at her brother's feet.

'Her parents were aware but they didn't take it seriously enough. I know the mother would have taken it very seriously if the children had felt the same way about their father. But because there were four children it was a case of 'Well, we must all try and rub along together and it's natural to feel like this about a big brother'.'

One possible cause is that children who feel powerless within their family can empower themselves by dominating another sibling. Or a child who is given too much responsibility for their brothers and sisters can lash out at them in anger at their parents.

And there is anecdotal evidence that children who are smacked by their parents may respond with violence against their siblings.

Child psychologists urge parents to be careful how they handle the birth of a new child. An older child can experience overwhelming fears of loss of love and attention and if the transition is not handled in a balanced way it can spark off the intense jealousy that can breed violence.

Margaret McAllister, an educational psychologist, says parents' ill-judged comparisons between their children can be the harbingers of bullying. 'A parent might ask a child to model him or herself on another, or else blame the child for not living up to superior qualities in another sibling,' she says. 'But covert comparisons may be made by the child. If a child observes that a sibling is preferred, he or she will make the comparison - and react.'

Her advice is to look out for signs of trouble and act. 'If any parent thinks the relationship between their children isn't a healthy one, they should seek outside help. Go to a GP for referral to a therapist or ask teachers about seeing an educational psychologist.'

CAROL'S STORY: FOR YEARS I BASHED, BIT AND THUMPED MY BROTHER

I HATED my brother with a passion from the minute I set eyes on him. I would walk past his pram and, wham, in would go my fist. I saw him as the thing that came between me and my parents.

He was always the blue-eyed boy who was interested in everything and I was the foul little girl who wasn't interested in anything. I can see now I wasn't such an attractive personality as he was, but as far as I was concerned he got all the attention and I hated him for it. It was as simple as that.

When he woke up in the morning, I'd lock him in his room so I could be alone in the world. When it came to games I wouldn't allow him to play with anything unless I was in charge and dictated what he could do. We had a rope ladder in our playroom and if I wanted him off it, I would push him off. One day I pushed him too hard and when he landed he slit his arm really badly. I just hid as I knew I'd get in trouble for it. I was always being punished for bullying him. I had a pony and would chase him round the field on it, while he was on foot, and hunt him like a fox. Or else I'd sit him on it and give it a wallop and the pony would go galloping off.

For years I bashed him, thumped him, bit him, dragged him round, overpowered him and used physical force to get him to do what I wanted. I don't know what stopped me from killing him because I wanted him dead. If I'd had a gun during those angry times I definitely would have shot him. He was completely at my mercy.

My parents were aware of what I was doing. They used to spank me and send me to my room. And I'd just sit there and think: 'Right, when I get out, I'm really going to get you,' and I'd lure him off.

It got so bad that my parents eventually sent me to a different school. His handwriting was so little and scrunched up that they thought my bullying was making him introverted. And I think it must have done.

I don't remember anyone ever trying to find out why I was so angry and hateful. My bullying was just seen as normal behaviour for a bad child. And I had no idea at the time it was just love I wanted. I was angry with my parents for a long time but recently have come to understand they did the best they could. They had their own problems and didn't have enough time to give us.

I do feel sad this is the way I treated him. We haven't resolved things yet as it's a difficult subject to broach.

I'd be absolutely gutted if I found out my bullying had affected him emotionally in any serious way, though I'm sure it did have an effect on him. I have to forgive myself in some ways, too. I was an angry little girl who wanted her brother to share the pain she was going through. I couldn't come to terms with it if I just put it all down to my being evil.

MARY'S STORY: I WAS REGARDED AS A NEUROTIC MOTHER

RUPERT was born in 1962 and David 14 months later, in 1963, and I suppose that's why there was so much rivalry. Perhaps I had David too early.

The bullying started pretty much when they started playing together, at about two and three years old. It was easier to distract them when they were smaller but it got more difficult when they were school age.

Rupert would come in from school and I used to feel the tension go through my body because I never knew how he was going to be. It was nothing for him to come in and turn the kitchen table upside down. I can remember actually sending prayers up, 'Please God, put Batman on', because that was the one time I had peace and quiet.

Fights used to break out every day. It got to the stage when sitting on Rupert was all I could do to stop Rupert killing David. Everyday I'd be sitting on him, covered in bruises and I suppose David was, too. I think David was the target because he was the closest and he made a lot of noise, squealing, so it was rather satisfying for Rupert. I've got a tape recording my husband made of them and you can hear David yelling: 'No Rupert, no Rupert, no Rupert'.

Later on, David caught on to the fact that Rupert would get into trouble and would provoke Rupert and watch with glee when he got into trouble again.

There was jealousy. I think it started more because David was a rival in my affections and then it became more about personalities. Both boys were clever but David never had to work or revise, while Rupert had to slog away at it. In games Rupert always had to win and if he didn't, there would be a bit of violence. He never broke anything on David but he used to batter him. David wasn't nearly as strong and would just defend himself with words.

And I remember when my daughter was born at home. I was resting in bed and the cot was by the wall. Rupert came in with a wooden screwdriver and walked to the foot of the cot. He was just banging the screwdriver down in the cot, getting closer to the baby. I've never been so frightened in all my life. I was so exhausted after the birth I couldn't move or find the voice to shout out. He didn't hurt her but he was looking at me and wanting to get at me for having this other child.

I just remember the violence between the boys as one prolonged nightmare. I was always on guard, being against violence myself and having to watch it in my child was terrible.

I was on tranquillisers for nine years. My

husband worked nights and it was a very lonely time.

I knew Rupert's wasn't normal behaviour. I think he would be called hyperactive now. He went backwards and forwards to the hospital. I think I was really regarded as a neurotic mother and that the problems were of my own making because of the way I brought them up. My mother used to say they were the worst brought-up children in the area and a couple down the road used to say: 'What he needs is a damn good hiding.'

But Rupert did cause me to be violent sometimes. I had a wooden spoon I used to threaten him with. My last resort was always that, although it was against my beliefs. One day I just went for him with the spoon and broke it against his backside, I'm afraid, but it didn't make the slightest difference because Rupert was very tough.

In the end the doctors decided he was a latent epileptic and put him on pills, which he strongly objected to. Then after a couple of years I took him to another hospital and the specialist there said he wasn't a latent

epileptic.

One would have thought I absolutely hated Rupert, but it was quite the reverse. He's smashing now, one couldn't have a more warm, loving son. I look at him and think all that suffering was worth it. He was here at the weekend and was saying what a terrible child he was. But he said as far as his childhood was concerned, he was so glad he wasn't oppressed. He's married and thinking of starting a family and wants his children to have a similar upbringing. I think we had a choice of squashing it all out of him or just living with it. My parents would have squashed it out of him so I decided to live with it. If I hadn't, it would have destroyed him.

I don't think the violence ruined David's childhood but he always had to be afraid of Rupert and I think he resents that. It's affected my daughter very badly, not because she was frightened but because she didn't get the attention she needed. I didn't have the time with all that was going on.

She was an absolute angel and a very solitary child. I think she's suffering from that because she finds it quite difficult to communicate with people.

I regret those years I wasn't able to relax and enjoy my children. I'd planned this lovely family and they were all going to be friends. You visualise the times you're going to have but because of this problem it couldn't be as I'd hoped. I regret that.

DANIEL'S STORY: THERE WAS SO MUCH VIOLENCE IT IS ALL A BLUR

MY ELDER brother and I were very different right from an early age. We were even billed by our parents as 'Night and Day'.

I was very close to my parents. I played the cello and would practise every day with my mother, who was a musician. These sessions were closed to my brother, which must have made him unhappy. My parents represented the liberal intelligentsia - bookish, artistic and left-wing, and, unlike my brother, I shared all these interests.

So from the start he was a bit of a family outcast and started harbouring a great grudge and resentment - which was all to come down on me later.

The really deep, dark, bad time between us didn't start until he became 13 and I was 10. That period of my life was so bad that I have blocked most of it out. There was so much violence it has all become a blur and I find it hard to recall specific incidents.

I just remember being in fantastic pain and going for stretches of days and weeks of unbelievable unhappiness, in constant fear of my brother. I never knew when he'd decide to beat me up. It went on for years.

He would always do it when my parents weren't around. There'd be his knuckles pummelling my head or a punch in the back when they were just out of earshot. I remember being introduced to my parents' friends in the sitting room. We'd be standing side by side and all the time we were smiling politely and answering their questions, he'd be punching me hard in the back. But they couldn't see what he was doing.

His favourite form of scaring me was to come for me at night. I'd be fast asleep in bed and he'd come storming into my room and switch the lights on full - pretending he was looking for pencils or something.

It was almost Gestapo-like tactics, intended to scare me. And it did. No one knew what was going on and I didn't dare tell. There was a moral pressure not to - like thieves' honour among children. Anyway, if I'd told, he'd just have hit me harder. I was in this terrible double bind.

It wasn't just the violence because on the scale of one to ten it wasn't gross violence. It was the consistent psychological terror that went along with his bullying. Even though I was scared of him, I protected myself by laughing at him, which made it worse. But my wits were my only weapon.

Looking back on it, I can see what he was trying to do was to give me the bad feelings he had himself as the family misfit. Going from being son No 1 to son No 2 is very difficult, and I think we all handled it very badly in the family. From the start, my parents were anxious to fix an identity on us both, for us to be this convenient pair of opposites. But I'm not sure how different we were. Maybe deep down he was a frustrated artist.

Now I consider my teenage years as a whole area of my life that is black, gone. It's only now, at 41, that it's starting to occur to me that all the things I did afterwards, the way I turned out, my entire life story, have been driven by those years. Everything has been a reaction to it.

The number for ChildLine is 0800 11 11.