The Australian Temperament Project

The first 30 years
ATP Report – May 2013

2. Infancy and early childhood

By Ann Sanson and Frank Oberklaid

What is temperament?

Temperament refers to differences between individuals, visible from birth, in how they typically behave and react to their social surroundings. When the ATP began in 1983, there was virtually no Australian research on child temperament. The initial aim of the ATP was to study temperament in a large representative sample of Victorian infants, and to understand how it affected their social and emotional development through childhood.

In the early years of the study, we developed simplified questionnaires (now widely used in child development research both in Australia and overseas) to assess temperament in infants, toddlers and young children.4121342 We identified several important aspects of temperament, including: sociability - the tendency of a child to be shy or outgoing in new situations and when meeting new people; reactivity - how strongly a child reacts to experiences and to frustration; and persistence - the extent to which a child can stay on task and control their attention, despite distractions and difficulties (see Table 2.1). These dimensions also reflect the capacity of an individual to manage, or self-regulate, their own feelings, attention and behaviour. Other aspects of temperament that were somewhat less important included rhythmicity (e.g., regularity of eating and sleeping patterns) and activity level. We found that children tended to remain fairly stable in their temperament from infancy to childhood, with few changing radically (e.g., from being very sociable to very shy) but many changing a little.37

Table 2.1: Dimensions, definitions and age-specific names of aspects of temperament studied in the ATP, by stage of development
Temperament dimension and definition Infancy and early childhood Primary school years Adolescence Adulthood
Sociability: tendency to be shy or outgoing in new situations and when meeting new people Approach/ sociability Approach
Approach Approach/ sociability
Reactivity: strength of emotional reactions to positive and negative experiences Irritability
Negative reactivity Negative reactivity
Positive emotionality
Persistence: capacity to maintain attention, despite distractions Persistence
Task orientation
Task orientation

The role of temperament in social and emotional adjustment

We have investigated links between early temperament and a number of aspects of later development and adjustment. For example, we examined whether having a "difficult" temperament (being irritable, shy, uncooperative) as an infant posed a risk for emotional and behavioural problems as preschoolers.31 We also looked at other infant factors, such as prematurity, colic and sleep problems, the mother's ease of relating to her infant, and the influence of family socio-economic status.1415 No single infancy risk factor was strongly predictive of problems at 3-4 years. But when two or more of these occurred together, rates of problems increased. A "difficult" temperament, and/or the mother having difficulty relating to her child, were always among the combinations of risk factors that predicted later problems. This work showed that temperamental characteristics may not directly lead to adjustment problems, but can create vulnerability when there are other risk factors in a child's life.

In several studies of children in the ATP who were born prematurely (before 37 weeks' gestation), we found that prematurity per se was not associated with having a difficult temperament or behaviour problems,3515 which is reassuring for parents, as it had previously been held that premature children were more difficult. In a series of studies we also found differences in the temperament style of infants born to families from differing cultural backgrounds, including families of Greek, Italian and Chinese heritage.81116 Other research during the toddler and childhood period revealed gender differences, with boys generally being rated as being more difficult and challenging for parents.3839


One aspect of temperament that we investigated in some detail from infancy to childhood was shyness (or low sociability).48 We visited a small sample of 6-7 year old ATP children and their families at home and found that observers' ratings of children's shyness matched well with their parents' ratings, showing that parents were accurate and valid reporters of their children's behaviour. We found that some parenting practices were linked to whether children who were shy as infants remained shy or became more outgoing, and whether non-shy infants developed shyness later. If parents were less child-focused, used physical punishment or used parenting methods that made their child feel guilty or anxious, children were more likely to remain shy or develop shyness. Those who had been shy as infants were more likely to overcome their shyness if parents were warm and nurturing, did not make them feel guilty or anxious, and did not push them to be independent too soon. These findings reinforce the importance of adapting parenting to a child's particular temperament style, and also show that parenting can help to modify temperament traits.


  • The ATP has demonstrated how individuals differ in temperament from birth, and how these differences matter for later development and adjustment.
  • From being virtually ignored in the early 1980s, temperament is now routinely included in studies of children's development. ATP questionnaires are now widely used in research on child development in Australia and internationally.
  • Important aspects of temperament include sociability (tendency to approach or avoid new situations and people), reactivity (self-regulation of emotional reactions) and persistence (self-regulation of attention).
  • Temperament is relatively stable over time, with many children showing small changes but very few children changing radically in their temperament.
  • More "difficult" infant temperamental characteristics can lead to behavioural and emotional adjustment problems in early childhood and beyond, particularly if there are other risks in a child's life. Temperament is important for multiple outcomes throughout childhood and adolescence and even into early adulthood.
  • Temperament can be modified through experiences such as the style of parenting a child receives. Shy infants were more likely to overcome their shyness if parents were warm, positive and understanding of their child's temperament.