At 4% months, infants were shown a series of brief choice trials between a stimulus that always remained the same and another that was different on every trial. The point when a consistent preference for the novel stimulus commenced was identified for each infant, and their preferences for the familiar and novel stimuli in trials preceding that point were examined. Infants who saw objects or faces as stimuli both exhibited selective attention to the familiar stimulus prior to preferring novel stimuli, although infants shown kaleidoscope patterns did not. These results document a preference for familiarity early in processing with a procedure that is not subject to ambiguities due to individual differences in processing speed or to collapsing data across infants. The results support a nonlinear model for memory formation during infancy and under-Requests for reprints should be sent to Beverly J. Roder, Infants to Adolescents,