Comment by tehayj

This is one http://www.publicaffairs.ubc.ca/wp-content/uploads/2012/05/I...

The other one is cited in this book (I read it there first) http://www.amazon.com/gp/product/1857883292/ref=as_li_ss_tl?...

Here is a not so scientific national poll about this http://www.dailymail.co.uk/news/article-2135843/Children-liv...