James Fallon, who himself has the neurological indicators of psychopathy, has been categorized as a "pro-social psychopath," a person who lacks empathy but is still capable of altruism. Or as one article phrased it, "you don't have to care about someone to be nice to them."
Professor Fallon discovered the neurological markers for psychopathy while studying brains scans for Alzheimer's research.
The lecture addressing the physical differences in psychopath's brains, shown at the start of the episode, is a real lecture Professor Fallon has given to many students before.