Question: Child care and aggression A study of child care enrolled 1364 infants and followed them through their sixth year in school. Later, the researchers published an article in which they stated that "the more time children spent in child care from birth to age four-and-a-half, the more adults tended to rate them, both at age four-and-a-half and at kindergarten, as less likely to get along with others, as more assertive, as disobedient, and as aggressive."33

(a) Is this an observational study or an experiment? Justify your answer.

(b) What are the explanatory and response variables?

(c) Does this study show that child care causes children to be more aggressive? Explain.