Parents who wonder how their offspring will turn out should look at what they are like at the age of three, scientists say.
Research has revealed that most of an individual's character traits are fixed by that age.
So a bossy three-year-old is already on track to being a forceful adult while a shy child is likely to turn out a reserved grown-up.
Youngsters classed as "under-controlled" at three might not just be going through a phase — they are likely to grow into antagonistic, unreliable adults with anti-social habits.
The findings come from one of the broadest studies into human personality, which looked at 1000 individuals over a 23-year period.
Researchers interviewed the children at three, grading their character traits in broad categories.
After interviewing again 23 years later, researchers found most of the 26-year-olds displayed broadly the same traits.