TORONTO -- Selfless concern for the well-being of others may begin in infancy, according to a new study of nearly 100 babies.

Researchers at the University of Washington found that nearly all the 19-month-old toddlers gave a tasty snack to a stranger in need, even when hungry.

According to researchers, the findings not only show that infants engage in altruistic behavior, but also suggest that early social experiences can shape altruism.

“We think altruism is important to study because it is one of the most distinctive aspects of being human. It is an important part of the moral fabric of society," said lead author Rodolfo Cortes Barragan, a postdoctoral researcher at the university’s Institute for Learning and Brain Sciences or I-LABS.

"We adults help each other when we see another in need and we do this even if there is a cost to the self. So we tested the roots of this in infants."

In the first experiment, 19-month-old babies repeatedly and spontaneously gave a piece of fruit to a stranger and even more did so while hungry in a second experiment.

"The infants in this second study looked longingly at the fruit and then they gave it away," said I-LABS co-director Andrew Meltzoff in a press release. "We think this captures a kind of baby-sized version of altruistic helping."

For the study, researchers chose kid-friendly fruits -- bananas, blueberries and grapes -- and set up an interaction between child and researcher.

The goal was to determine whether the child would, without encouragement, verbal instruction or reinforcement, spontaneously give an appealing food to an unfamiliar person.

In the experiment, the child and the adult researcher faced each other across a table at I-LABS, and the researcher showed the child a piece of fruit.

What happened next was determined by whether the child was in the control group or the test group.

In the control group, the researcher gently tossed the piece of fruit onto a tray on the floor beyond their reach but within the child's reach. The researcher showed no expression and made no attempt to retrieve the fruit.

In the test group, the researcher pretended to accidentally drop the fruit onto the tray, then reach for it unsuccessfully.

That reaching effort -- the adult's apparent desire for the food -- seemed to trigger a helping response in the children, researchers said.

In the first experiment, more than half the children in the test group picked up the fruit and gave it to the adult, compared to four per cent of children in the control group.

In a second experiment when the babies were hungry, 37 per cent of the test group offered the fruit to the researcher, while none of the children in the control group did so.

In all cases infants could have retreated to their parent and eaten the food instead of giving it up.

Other primates have been found to co-operate and share resources under restricted conditions, but chimpanzees for example, don’t hand over food that they need themselves, the researchers said.

The study authors also found that children with siblings and from certain cultural backgrounds were especially likely to help, indicating that infant altruism is flexible.

The authors cited previous studies with adults that show positive influences of having siblings and being raised by parents from cultural backgrounds that place value on how much an individual feels connected to others, known as interdependence.

In this study, 81.25 per cent of the children were white, 14.58 per cent were multiracial, 6.25 per cent were Hispanic or Latino ethnicity and 4.17 per cent were Asian.

"We think certain family and social experiences make a difference, and continued research would be desirable to more fully understand what maximizes the expression of altruism in young children,” Barragan added.

“If we can discover how to promote altruism our kids, this could move us toward a more caring society."