Australian Government, Australian Institute of Family Studies

Patterns and Precursors of Adolescent Antisocial Behaviour

A collaborative partnership between the Australian Institute of Family Studies and Crime Prevention Victoria, Department of Justice.

Executive Summary of the First Report

Adolescence is a crucial time for the emergence of antisocial and criminal behaviour which, for some, persists into adulthood, at considerable cost to individuals, families and the wider community. Much research has been devoted to the identification of risk factors associated with the occurrence of criminal and antisocial behaviour, with the aim of preventing such problems. However, much of the research has been cross-sectional or covered restricted age spans, conducted in other countries, employed disadvantaged samples, and focused on males. Its applicability to the Victorian and Australian context is uncertain.

Few Australian studies have examined the precursors and pathways to antisocial behaviour from the earliest years of life. The present study, a collaborative project between Crime Prevention Victoria, Victorian Department of Justice, and the Australian Institute of Family Studies, uses data from the Australian Temperament Project to describe patterns and precursors of antisocial behaviour among a representative community sample of Victorian adolescents.

A more comprehensive account of the study may be found in the First Report of the project. Appendices containing details of the statistical analyses conducted are also available. For copies, contact Crime Prevention Victoria

Australian Temperament Project

The Australian Temperament Project (ATP) is a large scale, longitudinal study that has, to date, followed Victorian children from infancy to 17-18 years of age. The initial sample comprised 2443 infants (aged 4-8 months) and their parents, who were representative of the Victorian population at that time (1983). In total, twelve waves of data have been collected, via annual or biennial mail surveys. Using age-appropriate measures, data have been collected on aspects such as the child's temperament, behavioural and emotional adjustment, academic progress, health, social skills, peer and family relationships, as well as family functioning, parenting practices and family socio-demographic background. Parents, teachers and the children themselves have acted as informants at various stages during the project. During the last three data collection waves in 1996, 1998 and 2000, when participants were aged 13-14, 15-16 and 17-18 years, adolescents answered questions regarding their engagement in antisocial acts.

Frequency of antisocial acts across the adolescent years

Antisocial behaviour was quite common among ATP participants over the period 13-14 to 17-18 years. The most common type of antisocial acts were property offences, with approximately 10-20 per cent of participants engaging in acts such as theft or vandalism. Cigarette and alcohol use were also relatively common (39 per cent and 85 per cent respectively, at 17-18 years). However, fewer participants had used marijuana (increasing from 6 per cent at 13-14 years to 19 per cent at 17-18 years) and very few (less than 4 per cent) had used 'hard drugs'. Authority conflict and violent antisocial acts were much less common, with the exceptions of skipping school (a high of 43 per cent at 17-18 years) and involvement in physical fights (a high of 34 per cent at 13-14 years). About one in ten participants had been in contact with the police for offending, but only a very small number had been charged (2-3 per cent), appeared in court (about 1 per cent), or been convicted of a crime (less than 1 per cent).

Frequency of antisocial acts among males and females

Skipping school, alcohol use and cigarette use were the most common antisocial behaviours for both males and females. A higher proportion of males than females had engaged in violent and drug-related antisocial acts such as physical fighting (for example, 52 per cent of males at 13-14 years compared with 15 per cent females); or been suspended/expelled from school (ranging from 6 to 9 per cent males compared with 2 to 4 per cent of females); committed property offences such as driving a car without permission (5-19 per cent males; 2-11 per cent females) and damaging property (19-32 per cent males; 8-11 per cent females); and been in contact with the criminal justice system (for example,19 per cent males and 6-8 per cent females had been in contact with the police for offending). Females, on the other hand, were more likely than males to have engaged in graffiti during early adolescence (11 per cent females compared with 7 per cent males at 13-14 years).

Patterns of antisocial behaviour over time

Different patterns of antisocial behaviour were identified among participants over 13-14, 15-16 and 17-18 years of age, leading to the formation of three groups. These were: 844 'Low/non antisocial' (those who exhibited no or low levels of antisocial behaviour at all timepoints); 88 'Experimental' (those who exhibited high antisocial behaviour - three or more different antisocial acts in the past year - at only one timepoint during early-to-mid adolescence); and 131 'Persistent' (those who reported high antisocial behaviour - three or more different antisocial acts in the past year - at two or more timepoints, including the last data collection wave at 17-18 years).

Predictors of antisocial behaviour across time

No significant differences were found between the two antisocial groups and the low/non antisocial group during infancy and early childhood. The first group differences emerged at the beginning of primary school (5-6 years). Clear and consistent differences between the persistent and low/non antisocial groups were observed from this time on. During mid childhood, the persistent antisocial group had higher levels of acting out, aggressive and hyperactive behaviour problems, and were more inclined to display volatility and to experience difficulties in maintaining attention than the low/non antisocial group. In late childhood, the persistent antisocial group continued to display problematic behaviour, and in addition were less cooperative, had poorer self control, had poorer relationships with parents, and were more likely to have friends who engaged in antisocial behaviour.

The experimental and low/non antisocial groups did not differ significantly until early adolescence. During adolescence, the experimental group resembled the persistent group on many domains, although generally was less dysfunctional. The two antisocial groups were significantly more problematic than the low/non antisocial group on a wide range of domains, including school progress, attraction to risk taking, coping styles, parent-child relationships, and parenting style. Towards the end of adolescence, this pattern of differences appeared to change, with the experimental group becoming more similar to the low/non antisocial group.

Predictors of antisocial behaviour across domains of functioning

Group differences typically centred on temperamental characteristics such as negativity, volatility and low persistence, as well aggressive, acting out and hyperactive behaviour problems, to the disadvantage of the antisocial groups. Powerful group differences were also observed in the domains of social competence, association with antisocial peers, school adjustment during adolescence, coping styles and involvement in risk-taking activities. Less powerful but significant group differences were also observed in family structural characteristics, parenting practices, and family relationships.

Gender differences in the predictors of antisocial behaviour

The effects of gender on the prediction of antisocial behaviour were investigated by (1) controlling for the effects of gender, and (2) conducting separate analyses for males and females. These analyses revealed a similar pattern of results to those described above, however, group differences during the early to mid primary school years were generally fewer, when sex-specific analyses were conducted.

Group differences over time

Graph of group differences over time

Key findings

  1. Some degree of antisocial behaviour is 'normal' in adolescence

    Consistent with previous research, the findings of this study suggest that some degree of antisocial behaviour is common among adolescents. However, there are distinct patterns both in the timing, the frequency, and the nature of the antisocial behaviours, which needs to be taken into consideration by prevention strategies.
  2. Early interventions to divert children from pathways to persistent antisocial behaviour are most appropriate during the primary school years for the majority of young people

    The current findings suggest that parents, teachers, clinicians and policy makers should focus on the early primary school years as a critical time for intervention in attempting to prevent the development of persistent antisocial behaviour. In this study, group differences first emerged at the age of 5 to 6 years (the commencement of primary school for most participants), suggesting that this period represents an early point in developmental pathways for the majority of children.

    It is widely recognised that interventions during the earliest years of life are critical for the prevention of numerous emotional and behavioural problems (for example, hyperactivity, attention-regulation problems). Hence, more broad-based interventions (for example, home visiting programs), during infancy and early childhood, which aim to prevent the development of problems before they emerge, may also prove beneficial. Infants and young children whose sociodemographic and familial characteristics place them at increased risk of later developing antisocial behaviour would particularly benefit from such preventative efforts. Nevertheless, the current results suggest that when targeting the pathways to persistent antisocial behaviour, the focus should be on the early primary school years as a crucial period to intervene.
  3. Persistent antisocial youth exhibit a distinct profile

    Individuals who went on to engage in persistent antisocial behaviour during adolescence were consistently reported to be more aggressive, more disinhibited, and more temperamentally reactive from mid-childhood onwards than individuals who later engaged in little or no antisocial behaviour. Furthermore, from late childhood, this group exhibited lower social competence, and associated more frequently with antisocial peers. Given the consistency of these findings, it may be possible to identify children who are at risk of developing persistent antisocial behaviour at quite a young age, for whom targeted interventions may be beneficial.
  4. Interventions targeting experimental antisocial behaviour need to be multi-faceted and focus on the early secondary school years

    Individuals who engaged in transitory antisocial behaviour during mid adolescence had shown clear signs of dysfunction from the early adolescent years, following the transition to secondary school. While they showed no signs of adjustment difficulties and were similar to the low/non antisocial group during childhood, in the early adolescent years they became more 'difficult' temperamentally, more aggressive, began to experience difficulties at home and at school, and were likely to have formed friendships with youth who also engaged in antisocial behaviour. Due to the wide range of difficulties exhibited by individuals displaying experimental antisocial behaviour, interventions aimed at preventing this type of behaviour should be multi-faceted and targeted at the early secondary school years. It will be important to follow the trajectory of this group into young adulthood, to ascertain if their problems were truly transitory.
  5. Precursors of antisocial behaviour are similar for males and females

    When differences between antisocial groups were examined separately for males and females, differences generally emerged at the same times and in the same domains for both sexes. These findings suggest that interventions aimed at preventing the development of antisocial behaviour may be used equally well with males and females.
  6. Peer relationships and their influence

    The existence of friendships with other antisocial youth was one of the most powerful risk factors for both persistent and experimental antisocial behaviour identified by this study. Such friendships were evident from as early as 11-12 years of age, and prior to the onset of antisocial behaviour. Other aspects of peer relationships also appeared important. The low/non antisocial group members were more attached to their peers (had greater trust and communication), and more frequently interacted with peers in a structured setting (for example, while playing sport). The two antisocial groups, on the other hand, appeared to spend more time with peers, but their time together was more likely to be unstructured.
  7. The role of family environment

    There were few significant differences between the three groups on socio-demographic characteristics such as family socioeconomic status, parental education, occupational, and ethnic background, and number of children in the family. However, within-family processes, (for example, the parent-child relationship, the degree of warmth and conflict in this relationship, alienation from parents, family cohesion, and marital conflict and breakdown) were important contributors to group differences. Parenting style was also important, with parents of antisocial youth more prone to use lower supervision, less warmth and more harsh discipline. In general, family environment factors were less powerful in impact than individual child characteristics.
  8. The importance of school adjustment

    Clear group differences in school adjustment and school bonding were evident during the secondary school years. Both the persistent and experimental groups were observed to have more difficulties adjusting to school, and to exhibit lower levels of attachment to school, than those in the low/non antisocial group. These findings suggest that the manner in which an individual adapts to the school environment, the way in which the school accommodates the child's individual characteristics and needs, and adolescents' attitudes about schooling, are important predictors of adolescent antisocial behaviour.

In summary, this First Report has documented substantial group differences between adolescents who engage in high levels of antisocial behaviour and those who do not, which are evident from the early primary school years on, and increase in strength and diversity over time. The most powerful group differences emerge in intra-individual characteristics such as temperament, behaviour problems, levels of risk-taking behaviour and coping skills, and in the domains of school adjustment and peer relationships. Significant group differences in aspects of the family environment were also found. These findings have important implications for the content and timing of interventions aimed at preventing the development of antisocial behaviour.

A later report will include an examination of differences between adolescents who engage in violent antisocial acts versus those who engage in non-violent antisocial acts, an investigation of factors which may have a protective effect against the development of adolescent antisocial behaviour, and an investigation of the effects of community factors on the development of adolescent antisocial behaviour.

For further information about Patterns and prescursors of adolescent antisocial behaviour contact:

Crime Prevention Victoria
GPO Box 4356QQ
Melbourne, Victoria 3001
+61 3 9651 6933
Web: http://www.justice.vic.gov.au/
Email: crime.prevention@justice.vic.gov.au

For further information about The Australian Temperament Project contact:

Australian Institute of Family Studies
300 Queen Street
Melbourne Victoria 3000
+61 0 9214 7888
Web: http://www.aifs.gov.au/
Email: atp@aifs.gov.au