Even for the strongest individuals, their commitment level or willpower is not always constant. Willpower is like a battery. As you exercise your willpower throughout the day, the battery power starts to decline. What drains your battery? Fatigue, negative emotions, low blood sugar, suppression of emotions, and even peer pressure will drain your willpower battery faster than anything else.
An interesting study gives more credibility to this idea that willpower may actually be made stronger if given periods of recess. Researchers had college students arrive to participate in an experiment regarding taste perception (or so the students thought). The students were instructed to come to the study hungry by abstaining from foods for three hours prior to their arrival.
When they entered the room, they were greeted by the scent of freshly baked chocolate cookies, which were piled high on a side table, next to a bowl of freshly washed and trimmed radishes. As they entered the room, they were divided into two groups. One group was told they could only eat the chocolate chip cookies and the other only eat the radishes. They were then left alone to walk around the room as they waited for the researchers.
Obviously, the radish group of students had to exercise their willpower to refrain from eating the chocolate chip cookies and only eat the plain radishes. After five minutes, the students were told that they needed to wait for their sensory perception of the food to fade before performing a new task. This next, unrelated assignment (or so they thought) was to solve a puzzle. Unbeknownst to the students, the puzzles were unsolvable. The researchers just wanted to see how fast the subjects would give up on the puzzles.