Two cross-sectional developmental studies of prosocial behaviors displ
ayed in natural settings by 2- and 5-year-olds using a prototype appro
ach are reported. In the first study, caretakers described the most pr
osocial child they knew, resulting in 20 attributes for 2-year-olds an
d 24 attributes for 5-year-olds. In the second study, parents rated th
e relative importance of each attribute in defining a child as prosoci
al. Results indicated more similarities than differences between the t
wo age groups and that research has; underrepresented the rich reperto
ire of naturally occurring prosocial behavior in young children, ignor
ing behaviors salient and important to parents (e.g., being cheerful,
sensitive, affectionate, friendly, and praising others) in favor of le
ss typical behaviors (e.g., donation of commodities to charity). Broad
er and more relevant indices of prosocial behavior are needed. Results
provide researchers with a data base which enables them to make infor
med decisions about the assessment of prosocial behavior.