“The most disturbing facet of this ubiquitous childhood disorder is an utter lack of empathy,” Mateo said. “These people—if you can even call them that—deliberately violate every social norm without ever pausing to consider how their selfish behavior might affect others. It’s as if they have no concept of anyone but themselves.”

“The depths of depravity that these tiny psychopaths are capable of reaching are really quite chilling,” Mateo added.