If you believed your teenager when they said they'd done their homework last night, then more fool you.
Because research has found adolescents are the best liars of any age group.
A study found that teens can juggle lots of information at a high speed meaning they make the fewest slips when fibbing - which makes their lies more convincing.
The researchers said they had the advantage because of changes to the frontal lobe of the brain which occur in 13 to 17-year-olds.
Bruno Verschuere, a professor of forensic psychology at Amsterdam University who headed the study, told New Scientist magazine: "Our findings suggest that whereas the lies of older people would be relatively easy to catch, [adolescents] would be more successful in getting away with their lies."