"It is a widely held stereotype that children who grow up without brothers or sisters may be 'oddballs' or 'misfits.' But new research undermines that notion." Only children adapt by their teens. "It has long been established that only children tend to have greater cognitive ability than those with many siblings, but some researchers have regarded that as counterbalanced by weaker social skills—which could potentially pose a problem for only children as they mature. Some of the most persuasive evidence for that view up till now comes from a 2004 study of more than 20,000 kindergarten children in the United States, which showed that teachers rated only children as having poorer social skills than their peers who had at least one sibling—reporting less self-control, fewer interpersonal skills and more behavioral problems."