Experimentally varying child behavior stimuli and then assessing the extent to which adult individual differences (especially in cognitions) moderate the effect of the child on the adult is a variation on the usual methods in child effects research. This method allows description of the role of child effects in more complex adult-child systems. Existing literature incorporating this approach is reviewed, with emphasis on the moderating effects of sex, personality, and perceptions. A previously unreported study is described as an example of a multivariate approach to exploring the relationships between adult individual differences and the effects of infant stimuli. The study suggests that experienced caregivers who do not have much liking for infants see themselves as likely to provide appropriate, but minimally social care for an infant. Conversely, the study suggests that inexperienced adults who like infants very much see themselves as providing more extensive and social caregiving, although it would not always be appropriate to the infant's state.