According to a recent paper entitled "Laughter Differs in Children with Autism: An Acoustic Analysis of Laughter Produced by Children with and without the Disorder" in the Journal of Autism and Developmental Disorders, children diagnosed with autism produce different laughs than their nonautistic peers.

"We revealed that children with autism produce very engaging laughs that we call 'voiced' laughs," said William Hudenko, the lead author on the paper and assistant professor of psychology at Ithaca College.

The study recorded laughter during a series of playful interactions with an examiner. The results showed that children with autism exhibited only one type of laughter, compared to two types of laughter for nonautistic children. There was no difference in laugh duration, frequency, change in or number of laughs per interaction.

"We hypothesized that children with autism may be expressing laughter primarily in response to positive internal states, rather than using laughter to negotiate social interactions," said Hudenko.

Hudenko specializes in child and family clinical psychology. His clinical experience involves children who have developmental disorders and disruptive behavior disorders.