This research examined the influence of social-, genetic-, and brain-based explanations on attributions of others’ behaviors. Participants were university students in Studies 1, 2, and 3. Participants read a vignette about an individual who possessed several undesirable behaviors and answered related questions. The first two studies had within-subjects designs. Participants in Study 1 were provided with social-, genetic-, and brain-based explanations for the individual’s behavior. The order of the genetic- and brain-based explanations was reversed in Study 2. Study 3 used (...) the same materials, but had a between-subjects design where participants were assigned to one of three groups that differed in their explanation: social, genetic, or brain. Participants also completed measures of social desirability and free will beliefs in all three studies. Consistently, biological explanations had more influence than social explanations on ratings of others’ responsibility, capacity for change, and sentencing considerations. There was inconsistent evidence across the three studies, however, that brain-based explanations had more influence than genetic-based explanations. Interestingly, Free will scores were associated with aspects of the individual’s behavior in the social condition but not in the biological conditions. Additional social cognition research is needed to determine whether brain-based explanations are just one specific instantiation of biological explanations or whether they are unique in this regard when it comes to the attributions we make about others’ behaviors. (shrink)