Subscribe to The Onion on YouTube: http://bit.ly/xzrBUA Citing the central role the process plays in cognitive development, a study released Thursday by the American Psychological Association found that boys do not reach emotional maturity until avenging the murder of their father. Like The Onion on Facebook: http://www.fb.com/theonion Follow The Onion on Twitter: http://www.twitter.com/theonion More Breaking News: http://www.theonion.com/video/