An April 2014 study published in the journal PNAS confirmed that people really do get hangry. The researchers studied whether low glucose levels were responsible for greater aggression in married couples. The scientists studied 107 couples and monitored their glucose levels twice a day for 21 days. To measure their aggressive impulses, the researchers asked each person to stick between 0 and 51 pins into a voodoo doll representing their spouse. The angrier the person, the more pins they used [source: Bushman et al.].
When the three weeks were up, researchers asked each couple to play a "game" designed to measure aggression. The scientists allowed the winner of the game to blast the loser with loud noise as both sat in separate chambers. There was a catch, however. Each person wasn't really turning up the volume. Regardless, those participants with low glucose levels believed they were hammering their spouses with high decibels of irritating noise.
"Results suggest that interventions designed to provide individuals with metabolic energy might foster more harmonious couple interactions," the authors concluded [sources: Bushman et al., Morin]. In other words, eat carbs before you argue.
The Ohio State study was just one of several linking self-control to glucose levels in the brain. One study concluded that those who drank a beverage high in glucose were less aggressive than those who did not. Still another study found an indirect relationship between diabetes, which is marked by poor glucose metabolism, aggressiveness and decreased self-control. Although causation is always hard to pin down, these studies suggested that a spoonful of sugar helps diminish violent or aggressive behavior [source: DeWall et al.].
Looking back, I should have eaten a candy bar before the meeting with Charlie.