A study of young children found that those with more body fat tended to have more "controlling" mothers; the San Francisco Chronicle concluded that "Parents of Fat Kids Should Lighten Up."²⁴

(a) Was this an observational study or a randomized controlled experi-

ment?

(b) Did the study find an association between mother's behavior and her child's level of body fat?

(c) If controlling behavior by the mother causes children to eat more, would that explain an association between controlling behavior by the mother and her child's level of body fat?

(d) Suppose there is a gene which causes obesity. Would that explain the association?

(e) Can you think of another way to explain the association?

(f) Do the data support the Chronicle's advice on child-rearing?

Discuss briefly. plo47