There is a new personal peace plan to help warring couples, called the Gendergram, which can often bring the most entrenched hostilities to a halt. The idea is that most relationship battles revolve around the same territory because each one of a couple will be making unspoken assumptions about what the other is supposed to do, without even realising it.

Take Charles and Sue. She says, "Do you love me?" To which he replies: "Of course I do." Sue: "How can I tell? You don't even like me much, except when you want sex." Charles, furious: "I go to work, I bring back the money, I help with the children, I don't sleep with anyone else. What more do you want?"

Charles and Sue are in the ring because they have different rules about how men and women behave when they love someone. "There are no rules about gender any more, so everyone makes up their own," says the originator of the Gendergram, Dr Mark White. "Then we assume that what we do is normal, and that anyone who does it differently is crazy/ impossible/ an insensitive slob."

We don't tell each other our rules because usually we aren't aware of them. For the lucky few, harmony reigns because they share the same unconscious rules: "we both help around the house", or "I do the money, you do the kids." But all too often there is a mismatch, and that's when the fights start. The Gendergram is a way of spelling out those hidden assumptions, which are all rooted in childhood.

To bring about a ceasefire:

1 Take a pen and paper, draw a circle in the middle, representing yourself as child, then write the names of significant people - Mum, Dad, aunts, baby-sitter - with a plus for the positive ones and a minus for the negative.

2 Write a line or two under each. What sort of things did they do? What did they tell you about men and women? How did they behave? How did you like it?

3 Look for a pattern. It can help to ask questions about what kind of gender rules were absorbed, such as "boys don't cry". Which ones did you learn from the way you saw other people behaving? What did you learn from the way you were treated?

4 Repeat for whatever stages of your life you feel are relevant, usually adolescence and childhood, and for the opposite sex.

Patterns will emerge quite quickly, and you can begin to discuss differences without climbing into the ring. Once you know where some of the patterns have come from, then you can decide whether they are useful, or could do with changing.