The significance of psychological and emotional decisions that people can take to give up harmful habits and lead a healthier life, is discussed. Health promotion leans heavily on insights from late 20th century psychology and belief that human behavior is driven by rational calculation. More than a million lives could be saved each year if people washed their hands at key times, because diarrhoeal and respiratory pathogens are carried on people's hands. Emotions play a significant part to interrupt a habit when the brain detects that an impending reward is greater, and to break unhealthy habits, campaigners need to target the emotions, because they are the decision makers.