Naturalistic assessment of maternal and infant interactive behavior using q-sorts has typically focused on rationally derived variables, such as maternal sensitivity and infant security. In the current study, behavior profiles characteristic of groups of young and adult mothers and their infants were derived empirically through q-factor analysis of the Maternal Behavior Q-sort (Version 3.0) and the Attachment Q-sort (Version 3.0). A three-factor solution best described the behavior profiles characteristic of young mothers. The identified factors were labeled: 'ignoring/neglecting versus interacting', 'accepting versus hostile/rejecting', and 'interfering'. The behavior of adult mothers was less variable and was described with only one factor, which corresponded to the 'accepting versus hostile/rejecting' factor. The factor solutions for infants of young and adult mothers were similar, with four identified factors, or behavioral profiles, discriminating between groups of infants with similar patterns of behavior: 'secure with mother', 'prefers visitor', 'socially withdrawn' and 'demanding with mother'. Infants of young and adult mothers differed with regard to their mean values on the first two identified factors. Results provide support for the relevance of rationally derived domains and criterion sorts in populations of both adult and young mothers, and suggest ways of progressing beyond the currently used, rationally derived variables in assessments of maternal and infant behavior in high- and low-risk populations.