Babies 'show jealousy' by three months

Although babies have traditionally only been thought capable of displaying basic emotions, a new study has shown that infants as young as three months actually show clear signs of jealousy. "Non-basic" emotions such as embarrassment, pride, guilt and jealousy were previously thought to develop only during the second year of a baby's life. However the research from York University's Department of Psychology found that babies seem to have an emotional response to human interaction between others.

Maria Legerstee, a professor at the department, said that when babies saw their mother's attention being distracted, they became agitated.

The study conducted on babies aged three, six, and nine months found that when mothers interacted with a female researcher in front of the babies, they reacted negatively by smiling less and turning away.

When researchers engaged in animated conversation with the mothers, deliberately excluding the babies, the infants became unhappy and tried to get their mothers' attention by screaming, kicking their legs and turning round in their seats.

Professor Legerstee said that the research sheds new light on the cognitive abilities of infants.

"Jealousy implies the formation of a social bond, and is a reaction to the presence of one who threatens this bond," she explained.

"This is strong evidence that infants understand that motives or goals guide our communicative behaviour."