They're glib and constantly turn on the superficial charm

Psychopaths are masters at presenting themselves well.

They are great conversationalists who can easily sprinkle chit-chat with witty comebacks and "unlikely but convincing" stories that make them look good, writes psychologist Robert Hare, creator of the Hare Psychopathy Checklist, in a post on Psychology Today.

Confronted with such charm, you may believe that the psychopath is a decent — delightful, even — person by the end of the conversation.

Hare writes that one of his raters once interviewed a male prisoner who threw in some compliments about her appearance, and by the end of the interview she felt unusually pretty.

"When I got back outside, I couldn't believe I'd fallen for a line like that," she said.