March 24 (UPI) -- Social biases can creep in early during child development, but scientists don't entirely understand how these in-group preferences and out-group hostilities first form.
In a new study, scientists contrived a situation in which children overheard negative comments about a new social group.
The experiment -- described Wednesday in the journal Child Development -- showed even a single negative comment can a lasting influence on a child's attitude toward the targeted social group.
"Findings from our work suggest that overhearing a negative conversation about an unfamiliar social group may influence intergroup biases among older children," lead author Emily Conder said in a news release.
"Caregivers should consider what is said around children and regulate the media they consume, as what children overhear about groups of people can influence their attitudes and behaviors," said Conder, a doctoral candidate at Vanderbilt University.
Previous studies have shown that children pick up both verbal and non-verbal societal biases from adults around them, and often generalize them -- showing the effect both types of reaction can have.
For the study, researchers recruited more than 120 children, mostly from White, middle-class families, in Nashville. Scientists collected demographic data on the children's guardians, who were made to fill out and sign consent forms.
More than two-thirds of the parents and guardians self-identified as White, while 19 percent identified as Black. Asian parents comprised 3 percent of the group, while 11 percent selected "multiple races or ethnicities."
For the experiment, groups of children met with a female researcher who introduced a novel, but unrelated, game.
While the children played, the experimenter received a pre-recorded Skype video call with either a child or adult. During the conversation, the researcher mentioned one of two fictional groups, "Flurps" or "Gearoos."
Some groups of children overheard negative comments about one of the two novel groups, such as: "The Flurps are bad people. They eat disgusting food and they wear such weird clothes." Other groups heard no comments.
The children were questioned about their attitudes toward the novel groups immediately after the experiment, and again two weeks later, the second time by a different researcher.
All of the participants were debriefed. Researchers explained to the children that neither of the two groups were real, but that if they were, they were certainly very nice people.
Data from the post-experiment interviews showed older children, ages 7 to 9, were less willing to befriend someone from the novel social group after hearing negative comments.
They also perceived the group as being less good and were more reluctant to try some of the group's cultural practices, such as taste their food or wear some of their clothing. The children's negative attitudes were stable two weeks later.
The negatives comments failed to have the same influence on younger children, ages 4 to 5. Whether the Skype caller was a child or an adult had no influence on the attitudes of the children, the researchers said.
In followup studies, scientists plan to investigate the effects of more direct messaging on the formation of out-group biases.