Sugar, Willpower & Belief
That food steadies the mind-body is practically axiomatic. But does energy intake need to be steady to keep the mind alert in demanding circumstances?
Popular theories suggest that glucose directly fuels brain functions, which would otherwise suffer from a lack of glucose. ~ Swiss psychologist Veronika Job et al
Personal belief about the relationship between mind and body affects the performance of the mind, notably willpower.
There’s a dominant theory in psychology that willpower is limited, and whenever you exert yourself to do a hard task or to resist a temptation, you deplete this limited resource. ~ American psychologist Carol Dweck
In a 1st experiment, participants were asked about their beliefs on willpower. They were given lemonade, sweetened with either sugar or a sugar substitute.
10 minutes later, participants took tests of mental acuity and self-control. Those who subscribed to a self-generating belief about unlimited willpower scored equally well whether their drinks were sugared or not. Those who felt that willpower was limited by immediate energy supply needed a sugar fix to perform as well.
In a 2nd experiment, some participants were told that willpower was a limited resource in dealing with a mental challenge. Those led to believe that willpower was tethered to energy intake needed sugar to perform as well as those not deluded.
In a 3rd experiment, participants were told that their drinks were sugary when they were not, and vice versa. Participants with belief in limited willpower still needed sugary drinks to do as well: the body was not fooled by what participants had been told about the specific drink.
The gut sends a signal of renewed energy to the brain; a cue that people who are positive about sugar’s importance to willpower are quick to pick up on.
But when you think willpower is abundant and self-energizing, you’re not paying attention to that. ~ Carol Dweck
Though the body ultimately needs sustenance to sustain mental functioning, the mind is its own taskmaster.
Ideas set free beliefs, and the beliefs set free our wills. ~ American psychologist William James