National Institute for Child Health and Human Development Child Care Outcomes Study—Report of Findings to Grade 5 and 6 (PDF): The study defined “child care” as non-maternal care over 10 hours per week. The main findings were that children who were in daycare centres had higher levels of behavioural/social problems such as aggression and cruelty, which continue without reduction; high quality child care is associated with better vocabulary scores than low quality child care; high quality child care is found most often in dad and grandparent care (the study previously estimated only 9% of child care settings were high quality).
kidsfirstcanada.org 