Watch footage of the experiments

Babies can tell friend from foe long before they can talk, according to research which suggests that the ability to assess other people’s motivations may be evolved rather than learnt.

A study in the United States has shown that, at both 6 and 10 months, infants clearly prefer people who help others over those who obstruct others or ignore them.

The findings, from a team at Yale University, Connecticut, show that even before children have learnt speech they have developed a kind of moral sense along the lines of the adage “do as you would be done by”. The very young age at which this emerges, before babies have had time to become heavily socialised, makes it likely that this is an evolved instinct rather than a behaviour learnt from parents or other adults.

“The presence of social evaluation so early in infancy suggests that assessing individuals by the nature of their interactions with others is central to processing the social world, both evolutionarily and developmentally,” the researchers said. “This capacity may serve as the foundation for moral thought and action, and its early emergence supports the view that social evaluation is a biological adaptation.”

In the study, which is published in the journal Nature,the team used a set of dolls to test the responses of babies aged 6 and 10 months. In the first experiment, the infants watched a wooden puppet with large eyes called “the climber”, which attempted repeatedly to climb to the top of a hill. A second doll was then introduced and would interact with the climber in different ways.

One doll, shaped like a triangle, would appear to help the climber up the slope by pushing it. Another doll, shaped like a square, would appear to hinder the climber by blocking its path and then pushing it back down.

After viewing these scenes, the scientists investigated the infants’ response by offering them the square and triangular dolls, and noting which one they wanted. All 12 of those aged 6 months reached for the helpful triangular doll, as did 14 of the 16 aged 10 months.

A second experiment reversed the scenario, with the climber moving downhill, to rule out the possibility that the children were responding to the direction of movement. In a third, babies of both ages preferred a neutral doll that did nothing to one that hindered the climber, and a helpful doll to a neutral one.

The results suggested that, from an early age, people were programmed to distinguish helpful individuals from unhelpful ones, the scientists said. This ability would have been critical to co-operative activities such as hunting, gathering and warfare.

They said: “The capacity to evaluate other people is essential for navigating the social world. Humans must be able to assess the actions and intentions of the people around them. “Many aspects of a fully fledged moral system are beyond the grasp of the preverbal infant. Yet the ability to judge differentially those who perform positive and negative social acts may form an essential basis for any system that will eventually contain more abstract concepts of right and wrong.”

Early learning

One month
Stares at faces, responds to sounds

Three months
Laughs, recognises parents’ faces

Six months
Imitates sounds and voices

Eight months
Says “mama” and “dada” to parents without distinguishing, begins to crawl

Eleven months
Says “mama” and “dada” to correct parent, stands briefly without support

Thirteen months
Can say two words beyond “mama” and “dada”, takes first steps

Fifteen months
Toddles well, vocabulary of five words

Source: www.babycentre.co.uk