Lycanthropy as a genetic shapeshifting condition. Among the types of shifters, lycanthropes are well known for their ability to go from fully human to fully non-human in form, but this is sadly often assumed to be accompanied by a similar change in their minds. For most lycanthropes, this is not true: they may struggle to control themselves when young and developing, but most retain their normal mental state and personality while transformed.
The problem is that late bloomers from non-lycanthropic families never developed the experiential skills necessary to remain themselves, so their first (few) transformations are often traumatic as they are overwhelmed by pain and hunted down by the people around them, people they may love and care for and not want to hurt are now turning on them, pushing them to flee and hide out to defend themselves with violence. These few but very tragic cases of shifters killing people near them has lead to much of the prejudice against lycanthropes, even though it is very rare — and is (almost) always in self-defense.