There are many ways to divide the “types of people in this world” in two, but here is one of my favorites: The people who easily see faces in inanimate objects, and the people who usually do not. This tendency to spot hidden faces in random patterns has a name — pareidolia — and it’s the subject of some new research out of Japan, which found that neurotic types are more likely to see, say, a menacing face in a plastic barricade.

Scientists at the NNT Communication Science Laboratory in Tokyo showed their study volunteers a sheet of paper flecked with random dots, asking them what, if any, shapes they saw, reports Moheb Costandi, a neuroscientist turned journalist writing for Brain Decoder. Before the connect-the-dots task, all the volunteers took a survey to assess their personality types and current moods. After analyzing their results, the researchers found that people who scored higher in neuroticism, and those who were in negative moods, were more likely to have found faces in the dots.

Costandi explains that the fact that neurotic people — who tend to be more tense, nervous, and emotionally unstable than non-neurotic people — seem to be predisposed for pareidolia is likely an evolutionary holdover: Their nerves put them on higher alert for threats, which may mean that they see danger where it actually isn’t. In this case, the researchers argue, that danger takes the form of a face. Same explanation applies to those in negative moods, though I’d also argue that once you start looking for faces in things, you kind of notice them everywhere.