"As far as we know, this is the first experiment confirming what we might have suspected: Lying by an adult affects a child's honesty," said Leslie Carver, associate professor of psychology and human development in the University of California, San Diego Division of Social Sciences.
Carver along with researcher Chelsea Hays, tested 186 children ages 3 to 7 in a temptation-resistance paradigm.
Approximately half of the children were lied to by an experimenter, who said there was "a huge bowl of candy in the next room" but quickly confessed this was just a ruse to get the child to come play a game.
The others were simply invited to play, with no mention of candy.
The game asked children to identify character toys they couldn't see by their sounds. Sounds and toys were pretty easy to pair: a "Tickle me" audio clip for Elmo; "I love cookies" for Cookie Monster; and "There is a rumbly in my tummy" for Winnie the Pooh.
One sound was a deliberately tricky exception: Beethoven's "Fur Elise", which is not associated with any commercially available character toy.
When the classical music cue was played, the experimenter was called out of the room to, supposedly, take a phone call - leaving the children alone in the room for 90 seconds and tempting them to take a peek at the mysterious toy making that sound.
The children were explicitly asked not to peek. On returning, the experimenter also explicitly asked the children to tell the truth. Cameras rolled the whole time.
The 5-, 6- and 7-year-olds who had been lied to were both more likely to cheat and then more likely to lie about having done so, too, researchers found.
About 60 per cent of the school-aged children who had not been lied to by the experimenter peeked at the tricky temptation toy - and about 60 per cent of the peekers lied about it later.
Among those that had been lied to, those figures rose to nearly 80 per cent peeking and nearly 90 per cent of the peekers lying.
It could be that the children were simply imitating the behaviour modelled by the adult, or it could be they were making judgments about the importance of honesty to this adult, researchers said.
Perhaps the children did not feel the need to uphold their commitment to tell the truth to someone who they perceived as a liar, they suggested.
The study is published in the journal Developmental Science.