威廉综合症患病儿童缺乏应有的社交谨慎感

Children with the genetic condition known as Williams syndrome（综合症） have unusually friendly natures because they lack the sense of fear that the rest of us feel in many social situations. Now, a study reported in the April 13th issue of Current Biology, a Cell Press publication, suggests that children with Williams Syndrome are missing something else the rest of us have from a very tender age: the proclivity（倾向，癖性） to stereotype（陈词滥调，老套） others based on their race. The findings support the notion（概念，见解） that social fear is at the root of racial stereotypes. The researchers say the results might also aid in the development of interventions designed to reduce discriminatory（有辨识力的） attitudes and behavior towards vulnerable or marginalized（排斥，忽视） groups of society.

"This is the first study to report the absence of racial stereotypes in any human population," said Andreas Meyer-Lindenberg of the Central Institute of Mental Health, Mannheim/University of Heidelberg, who coauthored（合著） the paper with Andreia Santos and Christine Deruelle of the Mediterranean Institute of Cognitive Neuroscience in Marseille.

Previous studies have shown that stereotypes are found ubiquitously（无所不在地） in typically developing children—as early as age 3—as they are in adults, Meyer-Lindenberg explained. Even children with autism（孤独症，自闭症） display racial stereotypes, despite profound difficulties in daily social interaction and a general failure to show adapted social knowledge.

In their study, the researchers showed children a series of vignettes（小插曲，小片段） with people differing in race or gender and asked the children to assign positive or negative features to those pictured. Typical children made strongly stereotypical assignments both for sex roles and for race, confirming the results of previous studies. On the other hand, children with Williams syndrome showed no evidence for racial bias（偏见，斜纹） .

"The unique hypersociable profile of individuals with Williams syndrome often leads them to consider that everybody in the world is their friend," Meyer-Lindenberg said. "In previous work, we have shown that processing of social threat is deficient in people with the syndrome. Based on this, we suspected that they would not show a particular preference for own-race versus other-race characters. The finding that racial stereotypes in children with Williams syndrome were completely absent was nevertheless（然而，不过） surprising in its degree."

The children with Williams syndrome did make stereotypical sex role assignments just like normal children. That finding suggests that different forms of stereotyping arise from different brain mechanisms, the researchers say, and that those mechanisms are selectively affected in some way by the genetic alteration（变更，修改） that causes Williams syndrome (the loss of about 26 genes on chromosome 7).