SUNDAY, Oct. 9, 2011 (HealthDay News) -- Children develop a sense of fairness and altruism, or selflessness, earlier than previously thought, according to a new study.
Researchers from the University of Washington found that 15-month-old babies could tell the difference between equal and unequal portions of food. This perception, the study authors noted, affected the babies' willingness to share.
"Our findings show that these norms of fairness and altruism are more rapidly acquired than we thought," study leader Jessica Sommerville, a University of Washington associate professor of psychology, said in a university news release. "These results also show a connection between fairness and altruism in infants, such that babies who were more sensitive to the fair distribution of food were also more likely to share their preferred toy."
In conducting the study, the researchers had 15-month-olds sit with one of their parents while watching two short videos of people sharing.
In one video, someone distributed crackers either equally or not equally between two people. The second movie was similar, but the people were given milk instead of crackers.
Since babies pay more attention when they are surprised, the researchers noted those participating in the study spent more time looking at the video when one recipient got more food than the other.
"The infants expected an equal and fair distribution of food, and they were surprised to see one person given more crackers or milk than the other," explained Sommerville.
The study, published Oct. 7 in the online journal PLoS ONE, also found there were differences in altruism among the 47 babies studied. The researchers had them choose between two toys: a simple LEGO block or a more elaborate LEGO doll. The researchers found one-third of the babies shared the toy they chose or preferred, while another third shared the toy they didn't choose. The final third group of children didn't share at all, which may have been because they were simply nervous around a stranger.
Comparing the two experiments, the researchers found that 92 percent of the babies who shared their preferred toy -- labeled "altruistic sharers" -- had spent more time looking at the unequal division of food. Meanwhile, 86 percent of the babies who shared the toy they did not choose -- called "selfish sharers" -- had paid more attention when the food was divided equally.
"The altruistic sharers were really sensitive to the violation of fairness in the food task," noted Sommerville. In contrast, the selfish sharers showed an almost opposite reaction.
The findings could be used to help foster sharing and cooperation among children, the research team suggested. They pointed out, however, that more research is needed to determine if fairness and altruism are innate qualities or ones that can be nurtured.
"It's likely that infants pick up on these norms in a nonverbal way, by observing how people treat each other," added Sommerville.
More information
The American Academy of Pediatrics has more about toddler growth and development.
