Yawning when others yawn，the study suggests，is a sign of pity and a form of social connection.Kids don't develop this deeply rooted behavior until around age four，the study has found.Kids with autism(自闭症)are half as likely to catch yawns.In the most serious cases，they never do.Yawning might help doctors to see whether the children are developing rightly.The work could also lead to a better understanding of the ways that people communicate and connect.

　　“Emotional infection seems to be a born thing that connects us together，”said Molly Helt，a graduate student in psychology at the University of Connecticut.“Yawning may be part of that.”Inspiration for her study came when she tried to get her own autistic son to clear his ears on an airplane.She repeatedly yawned at him，hoping he would yawn back.He never did.

　　“The fact that autistic kids don't do it might mean they're really missing out on that emotional connection with people around them，”she said.“The biggest thing people try to figure out after birth is how we become humans and understand that humans have minds that are different from others'，”she added.“Autistic people never seem to understand that.”

　　Like infectious laughter and crying，scientists have found that yawning is a shared experience that promotes social connection.Helt said it could fight stress after a period of being nervous and spread a feeling of calm in a group.

【2017高考英语三轮复习回归基础训练Unit4 北师大版】相关文章：

★ 2017届高考英语二轮复习课时训练：16（含解析）

★ 常熟市2014高考英阅读理解语一轮（暑假）训练题（2）及答案

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (31)

★ 安徽省淮南市2014高考英语一轮单项选择及文章训练（19）及答案

★ 四川省2016届高考英语一轮复习课时作业（30） Module 6 Animals in Danger 外研版必修5

★ 四川省广安市2014高考英语一轮基础训练题（6）及答案

★ 四川省2016届高考英语一轮复习课时作业（35） Module 5 Cloning 外研版选修6

★ 2017高考四川省广安市英语阅读理解一轮系列训练：1（含解析）

★ 英语2016高考二轮复习听力练习的三个阶段

★ 四川省2016届高考英语一轮复习课时作业（43） Module 1 Deep South 外研版选修8