For some people, an energy drink is an occasional rescue after a sleepless night. For others, cracking open a can has become as automatic as brushing their teeth. It happens before the morning commute, during the afternoon slump or immediately before opening the laptop. Psychology suggests that daily energy-drink consumption can become intertwined with habit formation, reinforcement, caffeine expectancy, fatigue management and withdrawal avoidance. In a systematic review of energy-drink studies, the most commonly reported reasons for drinking them included increasing energy or relieving fatigue, staying awake after insufficient sleep and improving concentration for academic work. That means the interesting question may not simply be Why do people like energy drinks? It may be: What psychological job has that daily can gradually learned to perform?
