Sources for scientific journals are provided below. New videos come out every Thursday so subscribe for more videos. Visit my Facebook page for more bite sized tips and psychology information https://www.facebook.com/BiteSizePsych Thanks again to Huntsman for the music. https://www.facebook.com/imhunterandimarapper?ref=br_tf Sources Number 1 http://www.ncbi.nlm.nih.gov/pubmed/17958704 http://psycnet.apa.org/index.cfm?fa=buy.optionToBuy&id=1988-33924-001 http://www.ncbi.nlm.nih.gov/pubmed/17259579 Number 2 http://www.ncbi.nlm.nih.gov/pubmed/16163517 http://psycnet.apa.org/index.cfm?fa=search.displayRecord&UID=2008-00342-002 Number 3 http://www.ncbi.nlm.nih.gov/pubmed/15250790 http://www.ncbi.nlm.nih.gov/pubmed/19386767 Number 4 http://link.springer.com/article/10.1007%2FBF01173206