This man is a pathological liar,” Senator Ted Cruz declared in a heated tirade against GOP frontrunner Donald Trump on Tuesday.

“He doesn’t know the difference between truth and lies,” Cruz continued, speaking at a press conference preceding the crucial Indiana primary. “He lies practically every word that comes out of his mouth. And in a pattern that I think is straight out of a psychology textbook, his response is to accuse everybody else of lying.”

Cruz, hurt that Trump accused his dad of being involved with the JFK assassination (really!), may not have much of a political career left after Tuesday’s Indiana primary, but his latest rant suggests he might make a decent psychiatrist. Even if Ted Cruz is the Zodiac Killer, he’s still right about Donald Trump.

Pathological liars have been documented in scientific literature for over 100 years, and though academics have yet to settle on the exact characteristics of the condition, common traits tend to pop up in papers on the subject, and Cruz did a surprisingly good job of identifying them.

1. Pathological liars lie a lot

This one’s a no brainer: Chief among the traits of pathological liars is the fact that they lie all the time. In a 2005 article published in the Journal of the American Academy of Psychiatry and the Law, Yale psychiatrist Charles C. Dike, Ph.D. suggested that lying is pathological when it’s “persistent, pervasive, and disproportionate.” Cruz, calling Trump out for the endless stream of falsehoods spewing out of his mouth, nailed this one.

2. Pathological liars don’t have an actual psychiatric disorder

The idea behind Dike’s second point is that you can’t call lying pathological if it’s being driven by a primary major psychiatric disorder; there’s a difference, after all, between someone who lies because of a clearly defined separate condition and someone who straight-up lies compulsively. Without evidence of compulsivity, excessive impulsivity, or brain dysfunction, Dike writes, “habitual lying, no matter how grand, is not a symptom, syndrome, or diagnosis, but just plain lying.” Good point, but Trump’s batshit crazy behavior makes this one hard to assess.

3. Pathological lies are filled with exaggerations and grand falsifications

When it was first described by the German psychiatrist Anton Delbrueck in 1981, pathological lying was referred to as pseudologia fantastica. Later, it was called “mythomania.” Both suggest that pathological liars have the tendency to get carried away with their lies, often to the point of fantastical, myth-worthy absurdity: Seriously, Donald Trump, did you think you’d get away with the JFK thing?

4. Pathological lying isn’t motivated by reward or other external factors

For pathological liars, there no pot of gold at the end of the dishonesty rainbow; as Dike points out, lying is “an end in itself.” It’s been suggested that pathological lying is a key trait of psychopaths, who have been known to derive “particular satisfaction” from being deceitful. Trump, whose face appears to exist in a state of permanent smugness, seems particularly satisfied, indeed.