Personality traits teachers observe in elementary school children may predict healthy–and unhealthy–behavior among adults decades later, according to a study published in the January issue of Health Psychology (Vol. 25, No. 1).

For the study, the researchers tapped a 1959–1967 dataset of 2,337 racially and ethnically diverse grade-school children in Hawaii. In that study, teachers assessed their students at the end of a school year on a range of personality traits, ranking them against their classmates on aspects of personality such as perseverance.

"Teachers, in many ways, are ideal judges of a child's personality. Teachers do get to know children quite well," says lead researcher Sarah Hampson, PhD, a psychology professor and senior scientist at the Oregon Research Institute.

In 1999, Hampson's team began contacting the now-grown children, asking them to participate in a follow-up study.

The 963 participants in the follow-up study filled out a 16-page questionnaire assessing their behavior and health, listing for example whether they smoked and how often they drank alcohol. Participants also provided height and weight to determine their body-mass index.

Then, researchers compared the questionnaire results with the personality assessments made by their teachers decades ago. They boiled down the teacher assessments using the "Big Five" personality model, which describes an individual's personality using five attributes and their opposites: extraversion, agreeableness, conscientiousness, emotional stability and intellect/openness to experience.

Overall, the study found that:

• Students rated as unconscientious by their teachers were more likely to be smokers as adults.

• Less agreeable girls were more likely to become smokers.

• Students rated as emotionally unstable were more likely to be drinking alcohol.

• Less agreeable students were more likely to have a higher body-mass index as adults.

• Unconscientious girls were more likely to have high body mass.

• Extraverted and conscientious girls and boys rated themselves healthier as adults.

By looking at how personality traits play a role in behavior such as smoking or overeating, researchers may someday be able to identify young people at risk for developing unhealthy behaviors as adults, says Hampson. The question of personality is important, because those unhealthy behaviors put adults at greater risk for developing heart disease and certain cancers, she says.

Additional studies will examine links between personality and students' educational attainment and socioeconomic status, Hampson says.