Genetic essentialism is a set of beliefs holding that certain categories have a heritable, intrinsic, and biological basis. The current studies explore people's genetic essentialist beliefs about criminality, how such essentialism relates to beliefs about appropriate punishment, and the kinds of judgments and motivations that underlie these associations. Study 1 validated a novel task, in which respondents estimated how possible it would be for a child to inherit criminal behavior from a sperm donor with whom they had no contact. Studies 2-4 used this task to address how genetic essentialist beliefs related to the harmfulness of a crime and the harshness of recommended punishment. Results indicated a tendency to essentialize both low- and high-harm crimes, though genetic essentialism was higher for more harmful crimes. Moreover, genetic essentialist beliefs predicted recommendations for harsher punishments, with retributive and protective motivations, as well as perceptions of recidivism risk, partially mediating this association. Further, Studies 3 and 4 found that genetic essentialism positively predicted support for harsh punishments such as the death penalty, as well as support for directing financial resources more toward law enforcement and less toward social support. Lay theories about criminality may have profound implications for decisions about appropriate punishment for wrongdoers, as well as broader policy decisions about crime, punishment, and resource allocation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).