Development of reactions to pain of inoculation in children and their mothers

This is a naturalistic study focusing on developmental changes in the immediate reactions of 183 Japanese children under 7 years old and their mothers to pain caused by inoculation of the children. Under the age of 5 crying was a typical child behaviour, whereas 5- and 6-year-olds showed facial expressions instead. Their mothers were generally empathetic to the children's distress on inoculation, but the empathetic reactions tended to decrease as the children grew older. However, children's crying per se did not necessarily cause the reactions, and the mothers of the older children tended to react to the children's pain with a smile. A greater proportion of 3-year-old females cried than males of the same age, but despite this their mothers had a stronger tendency to respond with a smile in comparison with the mothers of male children. The results were discussed with respect to development of emotional independence and competence of social manipulation by children.