Human babies not only are reliable triggers of tender feelings and protective tendencies, they also happen to be exceptionally fat compared to the newborns of most other species. These two facts are used to formulate a hypothesis predicting that overweight males, due to their great physical resemblance to babies, not only are perceived as cute, but also are associated with negatively evaluated traits (e.g., immaturity, lack of willpower) that are saliently inconsistent with traits required for adults. In this study, a great many physical features of adult males varying widely in weight were measured and correlated with subjective judgements. Providing preliminary support for the hypothesis, it was found that the features that were correlated with objective and perceived fatness (e.g., circularity of body parts, relatively large head, short and thick neck) also correlated with perceived babyishness. Perceived fatness and babyishness had curvilinear influences on the positive and prosocial appraisal of cuteness, but were primarily negatively related to perceived willpower and beauty. Results are used to formulate an alternative evolutionary perspective on social responses to overweight and obese individuals, emphasizing the uniquely human adaptive value of fatness and the misfiring of the underlying response mechanism under modern conditions of living.