Research report No. 17

Chapter 2. Australian Temperament Project (PDF 69 KB)

The Australian Temperament Project is an ongoing longitudinal study that has followed the development of a large group of young people born in the state of Victoria, Australia, from infancy onwards (for a fuller account see Prior et al., 2000, or visit the ATP website <www.aifs.gov.au/atp>). The project is a collaboration between researchers from the Australian Institute of Family Studies, the Royal Children's Hospital, the University of Melbourne and Deakin University. It is led and managed by the Australian Institute of Family Studies and is supported by a grant from the Australian Research Council. The research presented in this report was supported by the Transport Accident Commission of Victoria and the Royal Automobile Club of Victoria.

2.1 Survey methodology

The ATP commenced in 1983 with a representative sample of 2,443 infants and families from rural and urban areas of Victoria. Participants were recruited from a subset of Victorian local government areas selected by the Australian Bureau of Statistics to provide a representative sample of the state's population in terms of parental education level, occupational status and ethnic background. All parents with an infant aged between 4 and 8 months who visited their local Infant Welfare Centre¹ in the chosen local government areas during the first two weeks of May 1983 were invited to participate in the project. At that time, Infant Welfare Centres were very widely used, making contact with roughly 94% of all live births. As a final step in the recruitment process, comparison of the recruited sample to Census data confirmed that the sample was representative of the state's population (Sanson, Prior, & Oberklaid, 1985).

Fourteen waves of data have been collected via mail questionnaires to date. The first four waves of data were collected at annual intervals from infancy to 3-4 years of age. From the commencement of primary school up to 19-20 years, the data collections were conducted at two-yearly intervals, with an additional assessment completed during the first year of secondary school in order to track children's adjustment and wellbeing over this important developmental transition. More recently, there was a four-year gap between the survey waves at 19-20 years and 23-24 years.

The questionnaires have assessed many aspects of the young peoples' lives, including their temperament, health, social skills, behavioural and emotional problems, risk-taking behaviours, educational and occupational progress, and peer and family relationships, as well as family functioning, parenting practices and socio-demographic background.

At every survey wave, parents have completed questionnaires about aspects of family life and their child's functioning. School teachers also reported on the child's school and social progress, personal adjustment, and temperament style at the preparatory grade, Grade 2 and Grade 6 survey waves. From the age of 11 onwards, the young people themselves have completed questionnaires regarding a range of topics, including relationships with others, attitudes and beliefs, and personal adjustment. The availability of data from multiple informants for most domains and at most survey waves has provided researchers with a rich and reliable account of this cohort as they have progressed from infancy to early adulthood.

Approximately two-thirds of the original cohort is still participating in the study after 24 years. A higher proportion of the families no longer participating are from lower socio-demographic backgrounds or include parents born outside Australia. Nevertheless, there are no significant differences between the retained and no-longer-participating subsamples on any infancy characteristics.

The findings presented in this report are based on a sample of 1,000 young adults (61% female), who participated in the most recent survey at 23-24 years. This represents a response rate of 67% of those who were still involved in the study at this stage.

Driver behaviour measures

At the 2006 data collection wave, at 23-24 years of age, study members completed a series of questions about their driving experiences and behaviours. Parents provided parallel information on these topics. The measures used to assess these issues are summarised in Tables 1 and 2.

Statistical analysis strategy

Throughout this report, a number of statistical tests are reported in relation to each topic under investigation. When multiple statistical tests are undertaken, the likelihood of Type 1 error (a finding of significant differences when there is no such difference) is increased. To reduce this risk, an adjusted significance level of p < .01 is used. For reader interest, results that are significant at the conventional p < .05 level are reported as trends, but are not interpreted.

For categorical data, Pearson chi-square and logistic regression analyses were undertaken, with inspection of standardised residuals used to identify cells in which there was a significant departure from chance. For continuous data, t tests and analyses of variance were undertaken, with post-hoc tests used to investigate specific group differences.

Table 1. Road safety questions and response categories, ATP Young Adult Survey, 2006

Question	Response categories
Type of licence held	None, learner, car, and/or motorbike ("ever held" at 23-24 years)
Type of licence held now	None, learner, car, and/or motorbike
Length of time since first gained licence	Years and months
Ever had licence cancelled or suspended	Yes, no
In a normal week, how much time spent driving a car or riding a motorbike on Monday-Friday in daylight hours	Number of hours
In a normal week, how much time spent driving a car or riding a motorbike on Monday-Friday in night-time hours	Number of hours
In a normal week, how much time spent driving a car or riding a motorbike on Saturday-Sunday in daylight hours	Number of hours
In a normal week, how much time spent driving a car or riding a motorbike on Saturday-Sunday in night-time hours	Number of hours
Experience of crash/accident when s/he was the driver	Yes, no
Number of crashes/accidents when s/he was the driver	Number of times
Crash circumstances and result: driving alone, damage but no personal injury	Number of times
Crash circumstances and result: carrying passengers, damage but no personal injury	Number of times
Crash circumstances and result: driving alone, personal injury or death	Number of times
Crash circumstances and result: carrying passengers, personal injury or death	Number of times
How many crashes resulted in study member being fined or charged	Number of times
Number of times caught for speeding	Number of times
In last 10 driving trips, how many times drove up to 10 km/h over the limit	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove between 11 & 25 km/h over the limit	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove more than 25 km/h over the limit	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times did not wear a seatbelt (helmet if motorbike) at all	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times forgot seatbelt (helmet if motorbike) for part of the trip	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove when very tired	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times nearly fell asleep or fell asleep when driving	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove when affected by alcohol	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove when affected by marijuana/cannabis/THC	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove when affected by ecstasy (XTC, E, X, MDMA, eccies, etc.)	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times drove when affected by amphetamines (speed, uppers, fast, etc.)	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times talked on hands-free mobile phone when driving	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times talked on handheld mobile phone when driving	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
In last 10 driving trips, how many times used mobile phone function (e.g., received or sent an SMS) while driving	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times
How often make plans to avoid drinking and driving	Always, most of the time, sometimes, rarely, never
How often drink-drive after making plans to avoid it	Always, most of the time, sometimes, rarely, never
Actions taken to avoid drink-driving	Planned ahead & got someone else to drive, planned ahead & took taxi/public transport, planned ahead & found another way there, didn't drink alcohol, cut down on the amount drunk, counted/spaced drinks, drank low-alcohol beer, drank more water/soft drink, limited money spent on alcohol, left car there & was driven home by another, left car there & got taxi/public transport, left car there & found another way home, used breath-test machine, stayed overnight, slept in car, did nothing
In past month, drove when near or over the alcohol limit	No, yes, don't know
In past month, how many days drove when near or over the alcohol limit	Number of days
In past year, how many times been in contact with police for a driving-related offence	Never, 1-2 times, 3-4 times, 5-6 times, 7-9 times, 10+ times
Friends drive when they have had too much to drink	None, a few, most, don't know
Boyfriend/girlfriend/partner drives when they have had too much to drink	Not true, somewhat true, definitely true, don't know

Table 2. Road safety questions and response categories, ATP Parent Survey, 2006

Question	Response categories
Type of licence held by young adult	None, learner, car, and/or motorbike
Has ATP young adult bought a car since getting licence	Yes, no
Did parent help ATP young adult select the vehicle	Yes, no
What should have been the 3 most important factors in choosing car	Size, safety features, power/performance, fuel economy, price, comfort, vehicle type, manufacturer, reliability, special features, style/image/appearance, other
How influential parent was in vehicle choice	Very influential, somewhat influential, not very influential, not at all influential
What were the 3 most important factors in choosing car	Size, safety features, power/performance, fuel economy, price, comfort, vehicle type, manufacturer, reliability, special features, style/image/appearance, other
Has ATP young adult ever had licence cancelled or suspended	Yes, no
Young adult's experience of crash/accident when s/he was the driver	Yes, no
Number of crashes/accidents when s/he was the driver	Number of times
Crash circumstances and result: driving alone, damage but no personal injury	Number of times
Crash circumstances and result: carrying passengers, damage but no personal injury	Number of times
Crash circumstances and result: driving alone, personal injury or death	Number of times
Crash circumstances and result: carrying passengers, personal injury or death	Number of times
Did a crash result in ATP young adult being fined or charged	Yes, no, don't know
Has ATP young adult been caught for speeding	Yes, no, don't know
In general, how often does s/he drive up to 10 km/h over the limit	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he drive between 11 & 25 km/h over the limit	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he drive more than 25 km/h over the limit	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he drive when probably affected by alcohol	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he not wear a seatbelt/(helmet if motorbike)	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he drive when very tired	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he drive when probably affected by an illegal drug	Never, rarely, sometimes, often, always, don't know
In general, how often does s/he use a handheld mobile phone while driving	Never, rarely, sometimes, often, always, don't know

• ¹ These are now called Maternal and Child Health Centres.