Are people with dissociative disorders psychopathic?

Not really. The conflicts between alters are more internal than external.
Some are, most not. I have seen horribly psychopathic multiples that would not think twice of slicing your throat (true serial killers) and those that act out in many antisocial ways and belong in prison. Some I have met while they served sentences in prisons and some were still walking the streets (0ften in more way than one). One must never be naive when working with people with dissociative3disorders.
Generally no. Dissociative identity disorder (DID) is characterized by someone who typically has endured a horrific level of abuse and has unconsciously split off the good and bad aspects of themselves as a defensive way of staying safe, and deeply repressing the memories of the abuse that took place.