Susan Newman, a social psychologist at
Rutgers University and the author of
Parenting an Only Child, says that this is a myth. "People articulate that only children are spoiled, they're aggressive, they're bossy, they're lonely, they're maladjusted," she said. "
There have been hundreds and hundreds of research studies that show that only children are no different from their peers."[8] Similarly, a popular belief is held that only children have aversive[clarification needed] social skills, and therefore have a harder time making friends. A 2004 study of American middle and high school students found that such beliefs are false.
A 1987 quantitative review of 141 studies on 16 different personality traits contradicts the opinion, held by theorists including Alfred Adler, that only children feel maladjusted due to pampering.[19] The study found no evidence of any maladjustment in only children. The most important finding was that only children are not very different from children with siblings.
The main exception to this was the finding that only children are higher in achievement motivation, largely because their greater share of parental attention translates into increased parental scrutiny: This scrutiny, especially as compounded by only children's access to a greater share of parental resources, exposes them to greater absolute quantities of both reward when they exceed parental expectations and punishment when they fall short.
[20] A second analysis revealed that only children, first-borns, and children with only one sibling score higher on tests of verbal ability than later-borns and children with multiple siblings.
[21]
In his book
Maybe One,
Bill McKibben argues in favor of a one child policy based on this research. He argues that most cultural stereotypes are false, that
there are not many differences between only children and other children, and where there are differences, they are favorable to the only child. Aside from scoring significantly better in achievement motivation, only children score significantly better in personal adjustment to new situations. Only children are also more likely to make outside friends, whereas children with siblings tend to be "more parochial and limited in their understanding of a variety of social roles",
[23] but it is usually more difficult for them to do so, even in early life.
[24][25