Teenagers off the hook

Scientists have given teenagers an evidence-based excuse for bad manners, according to a study published this week.

Writing in the journal Child Development Temple University researcher Laurence Steinberg and his colleagues looked at over 900 individuals aged 10-30 from an ethnically and socio-economically diverse range of backgrounds. The team used an approach known as a "delay discounting task" to gauge an individual's willingness to forego a smaller short-term reward for a larger long-term return.

Compared with the adults in the study, teenage participants considered the future less and were more eager to settle for smaller short-term rewards. The authors attribute this to sensation seeking rather than a lack of self-control, saying that the brain circuits that drive thrill-seeking behaviour are most active between ages 10 and 16. These systems continue to mature after the age of 16, although the researchers found no signs of the youngsters' concepts about the future altering after the age of 16.

"Those who wish to use research on adolescent decision-making to guide legal policies concerning teenagers rights and responsibilities need to be more specific about which particular capacities are being studied - sensation-seeking or self-control - since they don't all mature along the same timetable," explains Steinberg.