Babies cannot differentiate between 'good' and 'bad' people

The 2007 study by Yale researchers provided the first evidence that six- and 10-month-old babies could assess individuals based on their behaviour towards others, showing a preference for those who helped rather than hindered another individual.

In the latest study, researchers from the Department of Psychology at Otago have shown that the earlier findings may simply be the result of infants' preferences for interesting and attention grabbing events, rather than an ability to evaluate individuals based on their social interactions with others.

"The paper received a lot of attention when it was first published, including coverage in the New York Times. It has received well over 100 citations since 2007, a phenomenal number over such a short period," Damian Scarf who led the study, said in a Otago statement.

"Our original motivation for reading the paper was merely interest. Obviously, the idea that morality is innate is extremely interesting and, if true, would raise questions about which components of our moral system are innate and also have implications for the wider issue of the roles that nature and nurture play in development," Scarf said.

The earlier study had concluded that infants can evaluate individuals based on how they interact with another individual, and that their ability to do this is 'universal and unlearned'.

After reviewing videos of the Yale experiments, the Otago researchers noticed that two obvious perceptual events could be driving infants' choices.

The study is published in the journal Science ONE.