PASADENA, Calif., July 15 (UPI) — A joint study by two U.S. universities found further evidence of a genetic contribution to autism, researchers said Tuesday.

The research found that some parents of autistic children evaluate facial expressions similar to their children, researchers from California Institute of Technology in Pasadena and the University of North Carolina at Chapel Hill said in a news release.

The researchers and autism experts from the two universities studied 42 parents — 15 of whom were classified as socially aloof — of autistic children with autism.

Researchers said parents participated in an experiment that measured how they make use parts of the face to judge emotions. They were shown expressions filtered so only certain parts of the face were visible and asked to decide quickly if the emotion were “happy” or “fear.”

“Aloof” parents relied more heavily on the mouth to recognize emotion than the eyes, research showed.

“We found that some parents who have a child with autism process face information in a subtly, but clearly different way from other parents,” said Cal-Tech neuroscientist Ralph Adolphs.

“It may lead us to finding genes that are responsible for the face-processing component in autism,” added UNC psychiatrist Joe Piven.

The findings will be published Thursday in the online edition of Current Biology.