A recent study by Stein et al. (2013) supports the NICHD (1991) study (page 68 of the AS textbook) that children who spent more time in day care centres when they were very young were more likely to have behaviour problems when they started school.
This longitudinal study recruited 991 families with a 3 month old child. All the mothers involved were over 16 (the average age was 30). The researchers carried out direct observations of the childcare provided by the mothers, plus direct observations of the care received by those children who went to day care or a childminder. When the children started school (when they were around four and a half years old), both their mothers and their teachers completed questionnaires about their behaviour.
Children who had more group care in day care were rated as having more behaviour problems (e.g. hyperactivity) than those who had home care, by both their teachers and their mothers. But they had fewer problems interacting with their peers. Children who had more care with a childminder were more likely to have problems interacting with their peers – but they were more likely to help others (called ‘prosocial behaviour’).
The strongest and most consistent influences on behaviour and emotional problems were found to come from the home environment and were related to socio-demographic status (the lower the status, worse the behaviour), maternal caregiving, parental stress/maternal mental health problems, as well as child gender – boys’ behaviour being more likely to cause problems at home and school. Non-parental daycare had only a small impact compared to these factors.