Men with long ring fingers are more likely to drive too fast, overtake on dangerous roads and park illegally, according to new research.
The study suggests bad driving may be programmed from birth because finger length is directly associated with exposure to the hormone testosterone in the womb.
Numerous studies have shown that a long wedding ring finger compared to the index finger in men can have a powerful effect on health and behavior.
Research suggests it is linked with increased male aggression and risk-taking.
But it also means men are better at sports such as athletics and football, more likely to succeed in the cut-throat world of high finance and may even be more fertile than those with shorter ring fingers.
Scientists believe exposure to greater levels of testosterone in the womb affects the way the brain works later in life.
The hormone appears to promote more masculine behaviour. But it also seems to activate growth of the wedding ring finger by stimulating testosterone receptors in bone.
