Resident-on-resident violence is more common than most people think, according to the lead author of a new study.

Dr. Mark Lachs of Cornell University in New York City and his colleagues examined police records of elderly people for a National Institutes of Health study. Among 747 people who were placed in long-term care during the course of the study, 42 were involved in 79 different incidents in which the police were called to nursing homes. It is being called only the second published report on resident-on-resident violence in nursing homes.

Incidents typically involved two residents physically assaulting each other. Competition over a seat in front of a TV, unwanted touching or a resident wandering into another’s room often set off the violence. More research should be conducted to determine the prevalence of violence in nursing homes and understand its triggers, Lachs said.