The number of only children in the U.S. has, according to Pew Research Center data, grown, with around 20 percent of households with children now raising a single child. Masry said only children "tend to interact more with adults," which can make them comfortable conversing with grown-ups early and using broader vocabulary sooner. The creator's video sparked over 10,000 comments, several of which were of only children agreeing with the sentiment shared. Contact Newsweek editors on this story: Kara Dolman and Emma Lee-SangNews Article Only Children Have One Key Difference—Psychologists Explain Why 0 Share Newsweek is a Trust Project member See more of our trusted coverage when you search. The number of only children in the U.S. has, according to Pew Research Center data, grown, with around 20 percent of households with children now raising a single child.