Definition of a psychopath: an abnormal lack of empathy. Hmmm...
From a book review The Fear Factor by Abigail Marsh:
In “The Fear Factor,” Abigail Marsh, a psychologist and neuroscientist, describes her research into that question with great verve. The results center on the ancient brain area called the amygdala. This region is known to be involved in processing emotions, including fear. And what do you see when you put psychopaths in a functional-MRI scanner? One, their amygdalas are on average smaller than ordinary people’s. Two, their amygdalas activate much less when shown images of frightened people. Indeed, when looking at various facial expressions, psychopaths easily name joy, surprise, confusion and so on—but they get stuck on fear. They don’t seem to know what it is.
https://www.wsj.com/articles/review-the-cruel-and-the-kind-1508280915
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Has anyone studied Whiny Donny's amygdala?
= new reply since forum marked as read
Just ask him. 
My therapist and other mental health professionals in her practice believe Dotard to be a Malignant Narcissist with possible Cluster B Personality Disorders. I have a brother who is a sociopath. It took many years to realize and come to terms with that fact. For self preservation, I had to sever ties with him. To this day, I cannot have contact with him without deep mental and physical distress. I have the same reaction to the pResident as do many others, I'm quite sure. He is sick, cruel, dangerous and without a thread of empathy.
https://www.psychologytoday.com/blog/neurosagacity/201702/malignant-narcissism-collision-two-personality-disorders
