At best, sibling rivalry can mature into friendly competition; at worst it can degenerate into arguments, estrangement and unhappiness all round. Sibling rivalry is an ancient tradition. The oldest book in Western civilisation, the Bible, tells the tale of Cain who murdered his irritating younger brother, Abel.

Few are moved to murder, but history is littered with examples of fraternal enmity. Not even Charlotte Brontė was above a bit of sisterly sniping. Her acid introduction to 1850 edition of Emily's Wuthering Heights describes its characters as 'unintelligible and, where intelligible, repulsive'.

Healthy competition or nasty warfare?
Rivalry between young siblings is inevitable: kids compete for their parents' time, attention and love, just as young animals compete for food. When those jealousies continue unchecked through adolescence into adulthood, real problems can occur.

At best, sibling rivalry can mature into friendly competition - think Conrans, Dimblebys and Therouxs. At worse it can degenerate into arguments, estrangement and unhappiness all round.

Gina was forced to take sides when the tension between her sisters escalated into all-out war three years ago. ' It created a huge rift in family. Mum took Maria's side and way she was treating Helen was outrageous, so we ended up arguing about it,' she says.

Gina didn't speak to her mother for a year and has little to do with Maria; her sisters still don't speak and Helen and her mother are only now starting to rebuild their relationship. 'I've given up trying to get Maria and Helen back together. I'm not on bad terms with Maria, but we don't have a close relationship any more and I avoid talking about either of them with my parents - it is the easiest way,' Gina concludes.

Spend some time thinking about things from your siblings' and parents' perspectives. The best advice when your siblings are fighting is: don't get involved - although that can be impossible, as Gina discovered. Try to keep your distance and refuse to take sides. Tell them their problem is with each other, not you, and you won't get involved.

Finally, don't expect them to play by the rules - they will try to recruit your support, make snide remarks about the enemy and draw you into battle. The only difference will be how subtle or overt they are. Stay firm, tell them that you are not willing to listen and either they change subject or you are going to have to end conversation.

Resentment and aggression
The relationships we form as children and emotional environment in which we spend our first years determine much of way we respond to adult life. If you constantly had to deal with aggressive behaviour from your brothers and sisters, aggression can become second nature. If you feel that your parents loved you less than your siblings, you may well find it hard to believe that you are loveable as an adult and may unconsciously seek out unequal or even abusive relationships that further that belief.

Talking it through with parents and/or siblings can help, but it is hardly an easy topic to broach and it can sound accusatory if listener is feeling defensive or guilty. Before you bring it up, spend some time thinking about it from your siblings' and parents' perspectives.

Learn to understand each other
If you are older, recognise that your sibling had no choice in being born and can't be blamed for subsequent disruption of your life. If you are younger, accept that your sibling was a small child struggling to come to terms with change rather than an evil monster. Imagine how tired and stressed your parents must have been and forgive them for not being perfect. Try to see it through their eyes - tackling a problem from another angle frequently helps to lessen hurt and guide you to your own solutions.

Next, prepare yourself for their possible responses. If life were like The Waltons, upshot would be group hugs, happy tears, love and positive reinforcement. Back in real world you may get answers you don't like, so be prepared by, again, thinking it through from their perspectives.

You may be pleasantly surprised; you may find your hurt feelings are based on a raft of misconceptions that your parents or sibling had no knowledge of; you might even discover that everyone else thought you were favourite. * The author is one of five children with battle scars to prove it. All names in this article have been changed.