This paper looks at the relationship between legitimate and expert social power types of preadolescent children over their perception of influence on their mothers’ purchasing behavior in Peruvian toy stores. The literature review takes into consideration the concepts of Social Power and the Influence in Family Behavior to then focus on Social Power within Family Behavior with the purpose of mainly developing four hypotheses regarding purchasing behavior. The methodology followed a nonexperimental transversal correlational design. A pilot sample size of 50 cases was used. The sample was based on an objective population of Peruvian mothers of families that live in northern Lima and that go to purchase toys with their children to major shopping centers. The results show that the expert social power as well as the legitimate social power has a strong relationship. In addition, both social powers have an impact on the perception of influence child–mother but not on the perception of influence mother–child. However, the test of moderation of the expenditure level on toy purchases did not have an effect on the context that was studied. The contribution shows that important changes are happening on the consumption behavior on the aspect of children influencing mothers and that for Latin American contexts, the level of expenditure still does not crucially affect the causality demonstrated.