A study conducted by Diane Poulin-Dubois of Concordia University has determined that children as young as fourteen months can determine whether or not an adult is a reliable source of information. Testers expressed delight that a toy was in a container, whether or not there really was one. Kids were eventually able to understand that certain testers could not be trusted to accurately report the presence of the toy:
Link -via Marginal Revolution | Photo by Flickr user xlordashx used under Creative Commons license
"Infants seem to perceive reliable adults as capable of rational action, whose novel, unfamiliar behaviour is worth imitating," the researchers said. "In contrast, the same behaviour performed by a previously unreliable adult is interpreted as irrational or inefficient, thus not worthy of imitating."
Link -via Marginal Revolution | Photo by Flickr user xlordashx used under Creative Commons license