Toxic people are people who constantly and consistently harm others, knowingly or unknowingly.

As licensed psychotherapist Babita Spinelli, LP, JD previously told mindbodygreen, these people can have a negative effect on others through their behavior, whether they’re trying to manipulate, control, or hurt others in any way.

Some people may have toxic traits without necessarily realizing the effect they have on other people, or be a toxic person in general, while others consciously engage in toxic behaviors.

According to clinical psychologist Perpetua Neo, DClinPsy, the latter is particularly common among dark personality types (psychopaths, narcissists, Machiavellians, etc.) who often correlate with toxic traits. “Then there’s an extra level where there are those who do it sadistically to cause drama or to watch someone squirm,” she tells mbg.