 Many studies of prosociality assume that the population structure is either homogeneous, meaning all individuals have the same number of interaction partners, or that the social good is of one particular type.
<clarity>  Many studies of prosociality assume that the population structure is either homogeneous, meaning all individuals have the same number of interaction partners, or that the social good is of one particular type.
 Many studies of prosociality assume that the population structure is homogeneous, meaning all individuals have the same number of interaction partners, or that the social good is of one particular type.