Typical four- or five-year-olds spend twice as much time with their siblings as with their mothers. Children really do rear each other and their relationships seem to waver between the bliss of shared play and the torment of rivalry and squabbling. You know the deal: one child is screaming because another one has finished off their favourite breakfast cereal, another child is roaring because a sibling took her toy - and it's not even 8 a.m. yet.

What's a parent to do? A friend of mine keeps a very large and impressive notebook, in which all the sibling snipes of the day are factually recorded. This gives the children a sense of justice, without making any judgments or laying blame. Try this and your children will soon see that the scores even out, she suggests.

Another approach is to let 'em at it. The latest in the Parent Talk Guide series, Brothers and Sisters (Hodder and Stoughton, £5.99 UK) advises parents to maintain a policy of peaceful non-intervention. When the children bicker, send them outside or else go upstairs, lock yourself in the bedroom and turn on the radio (it works for me).

Be impartial, never intervene and never blame - it's the children who are squabbling so don't be drawn in. And remember, he or she who cries loudest is not always the most innocent.

Make the children come up with their own solutions. If they cannot agree on the TV schedule in the next 10 minutes, the TV goes off for the rest of the evening. If they're fighting over the Lego, the Lego is taken away. Works like magic.

But you must intervene when a child is being bullied or hurt. Underlying issues of deep jealousy are something you have to talk with your children about individually. Most importantly, always praise your children for getting along well. Don't wait until they're squabbling to notice their behaviour.