Research at Glasgow's Strathclyde University shows that adolescent boys have such rapid growth spurts that their brains do not have time to get to grips with their size.

Most people are so used to their bodies and their relationship with their environment that they unconsciously know how to cope with it.

They can estimate what height of shelf they can reach or how many steps they can jump down.

But psychologists Dorothy Heffernan and Dr Jimmy Thomson say adolescent boys have to make rapid adjustments to their automatic responses, causing them to appear clumsy.

Reaching too far

They tested their theory on 75 Glasgow boys, aged 10 to 11, 12 to 13 and 14 to 15.

They asked the boys to predict how far they could reach from a standing position while still maintaining their balance.

The younger and older groups were fairly accurate, but the middle group were least successful in predicting their bodies' capabilities.

Boys in the 12 to 13 age group are undergoing the most rapid changes in body size and shape.

The researchers revealed their findings to a conference of the British Psychological Society (BPS) in Pitlochry, Tayside, on Friday.