A pioneering psychologist reveals how three emotions can provide the surest, quickest route to success in any realm. A string of bestsellers have alerted us to the importance of grit - an ability to persevere and control one's impulses that is so closely associated with greatness. But no book yet has charted the most accessible and powerful path to grit: our prosocial emotions. These feelings - gratitude, compassion and pride - are easier to generate than the willpower and self-denial that underpin traditional approaches to grit. And, while willpower is quickly depleted, prosocial emotions actually become stronger the more we use them. These emotions have another crucial advantage: they're contagious. Those around us become more likely to apply them when we do.