Spanking children slows cognitive development and increases risk of criminal behavior: http://www.sciencedaily.com/releases/2013/12/131211103958.htm
Spanking Linked to Kids' Later Aggression: http://www.webmd.com/parenting/news/20100412/spanking-linked-to-kids-later-aggression
Research on Spanking: It’s Bad For ALL Kids: www.psychologytoday.com/blog/moral-landscapes/201309/research-spanking-it-s-bad-all-kids
Children Who Get Spanked Have Lower IQs: http://www.livescience.com/7895-children-spanked-iqs.html
Spanking Linked to Long-Term Mental Health Issues: http://www.webmd.com/parenting/news/20120702/spanking-linked-long-term-mental-health-issues
9 Reasons Why You Shouldn't Spank Your Kids: http://psychcentral.com/blog/archives/2012/08/16/why-shouldnt-you-spank-your-kids-heres-9-reasons/