The haves and have-nots: Infants use wealth to guide social behavior and evaluation.

Biases favoring the wealthy are ubiquitous, and they support and bolster vast resource inequalities across individuals and groups; yet, when these biases are acquired remains unknown. In Experiments 1 through 5 (Total = 232), using multiple methods, we found that 14- to 18-month-old infants track individuals' wealth (Experiments 1-5), prefer and selectively help rich (vs. poor) individuals (Experiments 2 and 3), and negatively evaluate poor individuals (Experiments 4 and 5).

Infants preferentially help individuals who label objects conventionally.

Recent evidence suggests that infants engage in selective prosocial behavior toward some individuals over others; the ways in which infants are selective can illuminate the origins of prosocial behaviors. Here, we explored selective helping behavior, investigating whether a target recipient's prior adherence to, or defiance of, social conventions affects infants' subsequent likelihood of helping the target individual. 19-month-old infants (N = 120) participated in an interaction with an experimenter who correctly labeled common objects, incorrectly labeled objects, or labeled objects with nonsense English-like labels.

Infants' prosocial behavior is governed by cost-benefit analyses.

Cost-benefit analyses are central to mature decision-making and behavior across a range of contexts. Given debates regarding the nature of infants' prosociality, we investigated whether 18-month-old infants' (N = 160) prosocial behavior is impacted by anticipated costs and benefits. Infants participated in a helping task in which they could carry either a heavy or light block across a room to help an experimenter.