What are some statistics that relate to middle children?

According to an article in The Stir that cites several studies, middle children work best in group situations, are most well-adjusted and well-behaved, and are often successful and independent. Fifty-two percent of American presidents have been middle children as well as famous visionaries Martin Luther King Jr. and Nelson Mandella.

A Stanford University study examined middle children as being the least bold and least talkative compared to older or younger siblings. However, research at the University of Colorado has found that middle children also take more risks than their siblings. Katrin Schuuman, an author of the book "The Secret Power of Middle Children," agrees by stating that middle children think outside the box and feel less pressure to conform.