Hunger spurs anger in couples, study finds
Low blood sugar tied to lessened self-control and greater aggression
If you have something delicate to discuss with your spouse, best to do it after dinner.
A study shows that hunger in the form of low blood sugar leads to greater aggression and anger in married couples.
For 21 consecutive days, 107 couples measured their blood glucose levels each morning before breakfast and again before bedtime.
Each spouse was given a voodoo doll along with 51 pins and told, “This doll represents your spouse.” The couples were instructed to stick from zero to 51 pins into their dolls each night, depending on how angry they were with their partner.
Participants who had lower blood sugar levels stuck more pins into the voodoo doll, the Ohio State University-led team reports in the journal Proceedings of the National Academy of Sciences of the United States of America.
“Self-control requires energy, and that energy is provided in part by glucose,” the researchers wrote.
Glucose from food is converted into neurotransmitters that provide energy for brain functions. “Low glucose levels can undermine self-control because people have insufficient energy to overcome challenges and unwanted impulses,” they wrote.
“The brain accounts for only about two per cent of our body weight but it consumes about 20 per cent of the calories,” said lead author Brad Bushman, a professor of communication and psychology at Ohio State. “It takes a lot of brain food to exercise self-control.”
Anger is the emotion people have the most difficulty controlling.
The study, which took three years to complete, involved heterosexual couples married, on average, 12 years. The mean age was 36.
After completing a 10-item relationship satisfaction scale, the couples were instructed in the “voodoo doll task.”
Each spouse took a voodoo doll home, along with an instrument to measure blood glucose. They were told to stick pins into the dolls each night, alone and without their partners watching. Participants record- ed the number of pins they stuck into the dolls. Some people chose no pins. Three people chose 51 pins on at least one of the days. People jabbed, on average, 1.35 pins into the dolls each day over the 21 days.
Overall, “the lower their glucose levels in the evening the more pins they stabbed in their voodoo dolls ...” Bushman said. Even couples that reported high relationship satisfaction were more likely to express aggression if their blood sugar was low.
Although they didn’t measure whether people were dieting, dieters are especially likely to be cranky because they’re always deprived of food, Bushman said. “There’s a new word called ‘hangry,’ which basically is a combination of the words hunger and angry,” he said.
“Hungry people are often cranky people, and angry people are often very impulsive — they say things without thinking about it, they act without thinking first and they often regret the things they said and did.”
Low blood sugar levels may even increase the risk of violent criminal behaviour, including spousal abuse, the researchers said.
A healthy way to maintain healthy glucose levels, and possibly more harmonious relationships, is to eat vegetables and proteins.