This study, part of a naturalistic longitudinal study of infants being reared in a variety of family life styles, attempted to establish the extent to which differing parenting patterns affected early developmental outcomes. Subjects were 200 infants: 50 of single mothers who headed their family units, 50 of mothers in communal living groups, and 100 of two-parent nuclear families. All parents were Caucasian and from middle class or stable working class families. Infant development was assessed at eight months and one year of age. Four measures were derived from scores obtained on the mental and motor Bayley Scales of Infant Development (administered at eight months and one year) and four from the Stranger Situation Test (administered at one year). Parenting mode was analyzed in relation to Bayley and Stranger Test Scores, and 52 items on caretaking practices gleaned from home observation and parent reports. Although results indicated significant but not strong relationships between Bayley Scores and three of the caretaking factors, it was concluded that at one year of age, children being reared in widely varying life styles do not differ significantly on measures of intellectual development or separation responses. (SB)