One theory is that more educated people may be better able to calculate the risks of being caught out lying.
Middlesex University researchers analysed data on 6,000 people from deception tests used by psychologists.
Overall, men told more fibs than women. But while age had no effect, education had a significant impact.
Postgraduates had the lowest honesty rating, followed by graduates. Next were people who had vocational training, then those who completed secondary education.
The highest honesty rating was scored by those who did not finish school.
Notably, education had no effect on telling altruistic ‘white lies’ that benefit another person at a cost for the liar.
Dr Valerio Capraro, who led the study, said: ‘In order to lie, people must be aware of consequences and that requires some computational abilities, which may be more likely to be found in educated people.’