BABIES can tell when you have been lying to them, according to a new study.
Although babies are known for copying adults' behaviour, a new study shows babies will only imitate adults that have previously proven themselves trustworthy.
If an adult has previously displayed unreliable or dishonest behaviour, the baby is less likely to mimic them, according to LiveScience.
Researchers divided 60 babies into two groups. In the first group, "unreliable" experimenters looked inside a container while expressing excitement, and invited the babies to discover whether the box contained a toy or was empty. For that group's experiment, the box was empty.
The second group had "reliable" experimenters, so when the babies copied the adults' enthusiastic behaviour and looked inside the box, they found a toy.
In a second imitation task, each baby again observed the same experimenter that they had looked at during the box exercise. This time, the adult used her forehead instead of her hands to turn on a push-on light. The experimenter then watched to see whether the infant would copy her behaviour.
Sixty-one per cent of the babies in the "reliable" group imitated the irrational behaviour of using their foreheads to turn on the light, but only 34 per cent of infants imitated the unreliable testers who had previously lied them.
"This shows infants will imitate behaviour from a reliable adult," said researcher Ivy Brooker of the Concordia Department of Psychology.
"In contrast, the same behaviour performed by an unreliable adult is interpreted as irrational or inefficient, therefore not worth imitating."