Sweetened blood cools hot tempers: physiological self-control and aggression
-- DeWall et. al., Aggressive Behavior, Volume 37, Issue 1, pages 73–80, January/February 2011

"Aggressive and violent behaviors are restrained by self-control. Self-control consumes a lot of glucose in the brain, suggesting that low glucose and poor glucose metabolism are linked to aggression and violence. Four studies tested this hypothesis.... All four studies suggest that a spoonful of sugar helps aggressive and violent behaviors go down."