I think that according to the C's psychos do have a soul and can reincarnate, or at least that's how I interpret the discussion about Hitler and what happened to him after he died. Supposedly, he was in 5D and contemplating what to do next, or something to the effect. And whether to come back or not. It came up in one of the sessions.
I remember that the C's were telling us that the entity formerly known as Hitler is actually a souled being and has already reincarnated twenty years ago. His evilness was due to having made a pact with 4D-STS while in hospital at the end of WW I.
I think we have to differentiate between 3D souls striving for full STS and psychopaths who have not developed a soul. The latter should not be able to reincarnate, or so I think.