4 defining traits of a psychopath, according to a researcher who studies them

• The neuroscientist and psychologist Abigail Marsh explained what makes a psychopath.
• Marsh said that while psychopathy is a spectrum, all people with it have four defining traits.

Some people may assume that psychopaths are born from traumatic childhoods and depraved households, but a neuroscientist with 15 years of brain-research experience says her findings suggest that's not the case.

During a virtual seminar from the Science and Entertainment Exchange, an organization that connects the entertainment industry with science professionals, Abigail Marsh, a Georgetown University psychology professor and neuroscientist, said the root of their illness is often brain development.

"We do know that the severity of these traits is linked to characteristic brain abnormalities that seem to start early in childhood and then sort of progress," said Marsh, who also founded the research nonprofit Psychopathy Is.

Marsh said psychopathy exists on a spectrum from mild to severe, with some people being more manipulative, risk-taking, and threatening than others. Still, Marsh said they share four characteristics: pitilessness, remorselessness, an inability to love, and insensitivity to the possibility of harm.

Psychopaths have little to no pity or remorse for others

First, people on the psychopathy spectrum have trouble feeling pity, Marsh said.

When someone close to a psychopath feels sad or fearful, they can't understand the emotion, because it's something they don't feel themselves, she said.

Marsh gave the example of an elementary-school-aged boy she studied who'd videotaped his teachers and classmates screaming, crying, and evacuating as they reacted to what they thought was a terrorist attack on their school.

Similarly, people with psychopathy feel little to no remorse when they harm others mentally, emotionally, or physically, Marsh said.

She said she studied a boy whose teachers had expelled and suspended him from school so often that his mother lost her job because she needed to tend to him, then later checked in to a mental-health facility because of the stress. When Marsh asked the boy how he felt, he said it didn't affect him, she said.

"He said, 'You know, the things I do hurt her, but she doesn't really say how much, so it doesn't have any effect on me,'" she said. "So basically he was blaming his mom for his total absence of remorse for all the negative effects that had occurred because of his behavior."

Psychopaths don't understand love the way others do

People with psychopathy also have trouble feeling or understanding love, Marsh said.

"They do not experience close, loving bonds with other people in quite the same way other people do," Marsh said. "More than one child or adolescent I've interviewed said that they don't love anybody — not their family, not their friends."

Instead, people with psychopathy may refer to or think of loved ones as "associates" who can help them but are beneath them, Marsh said.

Psychopaths don't fear getting hurt physically or emotionally

Lastly, Marsh said, people with psychopathy have trouble understanding the emotion of fear.

"They're really insensitive to the possibility of future harm," she said. "In the words of one girl we studied, 'Nothing scares me. #Nothing.'"

She added that the threat of injury, going to jail, or disapproval wouldn't stop a person with psychopathy from doing what they please.

She said she studied a young woman who'd stolen her parents' car for a joyride, driven it into a tree, and flipped it over.

"She was completely unruffled," Marsh said. "The cops showed up at her house later, and she was sitting calmly on the couch, eating Doritos."