But now, seemingly adding weight to that myth, scientists have carried out research on sheep and goats - and discovered that the mother-son relationship is so close that it can determine sons' sexual preferences.

Researchers say they believe humans could act the same way.

Dazed and confused

K442 is a sheep who thinks he's a goat and it's all the fault of scientist Dr Keith Kendrick from the Babraham Institute near Cambridge in the UK.

"What we've done is to carry out a quite large scale experiment involving both sheep and goats where we've cross fostered between the two species. So that goat mothers have been rearing lambs and ewes have been rearing kids [goats]".

The idea was to see how much of their behaviour was determined by the mother and how much by genetics.

When the animals grew up the researchers carried out a series of experiments to find out which species the animals wanted to mate with.

The results have just been published in the journal, Nature.

The wrong sort of girl

"The most staggering finding was that when we tested them for their social and sexual preferences when they were sexually mature, the males showed almost tunnel vision in terms of their interest for female members of their foster species - that's the wrong species, not their own genetic species," said Dr Kendrick.

So the scientists ended up with some very confused animals: sheep that thought they were goats and goats that thought they were sheep.

Mother Love

The research suggests a powerful link between mothers and their sons - but is the same true of humans?

Although he can't carry out the experiment on humans, Dr Kendrick believes it is.

"There are similarities between the sheep and goats and humans and if you put this alongside the claims in humans that, for example, men end up marrying or having relations with women who look like their mothers; it does beg the question that perhaps the same kind of thing is going on in humans - but not to the same degree."

This suggests that the male brain is wired up differently to that of the female. Something that many people have probably thought for a long time.