The epistemological framework of problem-behaviour theory helps to understand the adolescent's development and changes according to a psychosocial multivariate approach which considers social environment, perception of the environment, and social behaviour.

In this perspective three extremely important problems on theoretical and applicative level were faced.

1) Can the involvement in problem behaviour during adolescence be predictive of problem behaviours during adulthood ?

A longitudinal study on 13-15 year old white middle class adolescents over a nine year period(1972-1981),analysed with a structural model, shows that there is no relationship between problem behaviour during adolescence and adulthood in the following areas: satisfaction with life, social role, income family life, friendship, health, self esteem, alienation political participation.

2) Is the transition to a non-virginity state the effect of the nature of adolescent development, or is it linked to psychosocial variables?

A four year longitudinal study on middle school students defined by "conventionality" or "non conventionality" of behaviour shows that in white youths and in Hispanic ones with conventional behaviour there is a virginity survival rate twice as high as that of non conventional subjects (65% vs 35%). This does not hold true for black subjects. If one considers values taking into account the integrity of the family nucleus, though, conventional subjects show a higher virginity survival, just like the others.

This shows a strong protective role of family integrity.

Conventionality and non conventionality were measured by evaluating whether independence was a more important value than success, if success expectations were high or low, if there was a greater or lower tolerance to deviance, if there were or were not friendships with problem behaviour, if there was involvement in problem behaviour, if there was commitment in school activities, if there was involvement in family life, and if there still was sexual inexperience.

3) Do protective factors moderate risk influence on problem behaviour during adolescence?

An index on risk factors and protective factors was constructed on personality system, environment and behaviour variables, controlled by economic state, sex, age, and family composition. Risk factors which contributed to the formation of the index were: low self-esteem, low success expectations, a sense of alienation and desperation (personality system), orientation towards friends and parents, and friend models with problem behaviour (perceived environment), disconnection with conventional institutions and the lack of success in school (Behaviour system). Protective factors considered for the index were: relationships with adults, the perception of a normative control from the outside, conventional friends' models of behaviour, good school results, being involved in groups and in social activities, attitude towards school and intolerance to deviance, religious faith, and voluntary activity. It is shown that protective factors interact with risk factors in such a way that when protection is high there is no impact of risk on problem behaviour, whereas when there is no protection there is a linear relationship between risk and problem behaviour.

These results appear determined to move the attention towards the promotion of protective factors rather than towards the prevention of risk factors, very common attitude in U.S.

Richard Jessor: "Problem-Behaviour Theory and the Life Course in Adolescence: Epistemology in Action". Presented at the First International Congress of Adolescentology, Assisi, Italy, October 22-24, 1993.

Key Words: Adolescence, Behaviour Theory, Risk Factors, Protective Factors, Research

Richard Jessor: Director of the Institute for Behavioural Science, University of Colorado, USA.