The way children sniff different aromas could form the basis of a test for autism, suggest researchers in Israel.
People spend longer inhaling the delightful aroma of a bouquet of roses than the foul stench of rotting fish.
The results of tests on 36 children, in the journal Current Biology, showed that there appeared to be no such difference in children with autism.
The National Autistic Society said smell could eventually become an additional tool for testing for autism.
Behaviour, social interactions and communication skills are all affected by autism and the disorder affects one in every 160 children globally.
It often takes until a child is at least two before it can be diagnosed.
'Somewhat surprising'
The children in the trial at the Weizmann Institute of Science took part in a 10-minute experiment.