A new study says the person you're hooking up with on Tinder could be a psychopath. The Dutch study found that almost one-in-four people on the dating app are already in a committed relationship, and those people are more likely to be psychopaths than single users. The study's author says non-single people who were also on Tinder reported higher scores on neuroticism and psychopathy than non-single people who were not on Tinder. They also reported more casual hookups than single users. The study suggests people with those personality traits might be more susceptible to using dating apps for infidelity purposes.