The Australian Temperament Project has followed a large cohort of Victorian children since their infancy in 1983, and the dataset includes some identical measures on the children in infancy and at 4 years to the first wave data of the Growing Up in Australia study. The authors have used this opportunity to compare children's temperament and behaviour over this 20 year period. They found little difference in children's temperamental characteristics, and no evidence that children today have higher levels of emotional or behavioural difficulties than children 20 years ago.