Neuroscientist Jim Fallon studies psychopathic killers, and why they do what they do. Is there something different about their brains genetically, due to damage, or is their behavior (murder) caused by environment? Interestingly, psychopathic murderers often have damage to their orbital cortex — a part of the brain just above the eyes — as well as certain genetic markers. Fallon explains in a fascinating, brief TED Talk what his research has revealed — including a personal connection to his work, as it turns out he’s related to a long line of murderers (uh-oh).

Discussed: why more men than women are psychopathic killers, how overdoses of serotonin in the womb desensitize young brains, how early trauma interacts with a particular “killer gene,” how Fallon’s cousin is Lizzi Borden (and other murderous family connections), and how Fallon is watching for more murderers to pop up in his own family.

You can also watch in high-resolution MP4 format (plays in QuickTime, Windows Media, etc.). Also, read more about Jim Fallon and psychopaths.