Teenagers from families with a history of alcoholism have brains wired for risk taking, a study has found.
The finding may help explain why alcoholism can run in families.
Scientists carried out brain scans on two groups of adolescents aged 13 to 15 while they performed a "Wheel Of Fortune" decision-making task.
Each participant was faced with risky versus safe probabilities of winning different amounts of money.
One group had a positive family history of alcoholism while the other did not.
Distinct differences emerged in the brain responses of the two sets of youngsters.
The group with a family history of alcoholism showed weaker responses during risky decision making in the pre-frontal cortex and cerebellum brain areas. Both are important for high level day-to-day functioning, including attention, working memory and inhibition.
"We believe that weaker activation of these brain areas, known to be important for optimal decision making, may confer vulnerability towards risky decisions with regards to future alcohol use in adolescents already at risk for alcoholism," said study leader Dr Bonnie Nagel, from Oregon Health and Science University in the US.
The findings are published in the journal Alcoholism: Clinical and Experimental Research.
Previous research has shown that adolescents with a family history of alcoholism lack inhibition.