Objectives: Although no genetic tests for violent behaviour are currently available, research is ongoing to isolate genes related to a propensity for violence. We explored the attitudes of parents and healthcare professionals toward behavioural genetic testing for violence.Design: The attitudes of healthcare professionals and the lay public about genetic testing of children were elicited for a range of conditions through interviews with healthcare professionals and focus groups with parents. All participants were informed that behavioural genetic testing was the only hypothetical (...) genetic test in our script and it was presented as the last condition.Participants: The healthcare professionals included both genetic professionals and paediatricians. Focus group participants were recruited through various community institutions in the southside of Chicago and nearby suburbs.Results: The healthcare professionals tended to medicalise behavioural genetics, and were opposed to testing unless treatment was available. They were also uniformly concerned about the potential harms of this information, including unintentional adverse effects from environmental changes. In contrast, parents wanted genetic testing for behavioural traits to be available even in the absence of proved medical treatments. Not all parents wanted to test their own children, and some parents were concerned about self-fulfilling prophecies. Some parents, however, felt the information was important for their understanding, and could be used to support environmental changes.Conclusions: While healthcare professionals medicalised behavioural genetics, parents focused on environmental causes and influences. Consequently, healthcare professionals do not want to offer testing if there is no clear treatment, while parents may want this information to shape environmental influences. (shrink)