When marketing a product, service, or experience, for example, is it more hedonic or more utilitarian? Are people buying it for pleasure or enjoyment, or more functional or practical reasons? If it’s more about enjoyment, emotional words like “awesome” and “beautiful” fit really well. Saying a movie is “heartwarming,” a destination is “inspiring,” or a meditation app is “fantastic” not only suggests those things are good but does so in a way that encourages purchase and action.

If the product, service, or experience is more about practical functionality, however, those same positive words may backfire. Less emotional words like “brilliant,” “flawless,” and “perfect” will be more persuasive. Calling a dictation app “brilliant” rather than “awesome,” for example, should encourage purchase and use.

The deepest principle of human nature is the craving to be appreciated,” wrote William James, the father of American psychology. It is impossible to be motivated and do great work if you don’t feel that somebody cares and appreciates what you do.

Studies have shown that for people to be happy and productive at work, they need to experience positive interactions (appreciation, praise) vs. negative (reprimands, criticism) with their manager/coach in a ratio of at least 3:1. (Watch out: For a marriage to work, you actually need a 5:1 ratio!!) So make it a simple habit to thank people each and every day —

and that includes using the word generously in emails to your team.

People change best by feeling good, not by feeling bad. Amy set herself up for success by thoughtfully using prompts to design changes. Those changes worked because they helped her do what she already wanted to do. And that success? That felt good.

The feeling of success is a powerful catalyst for change. Your confidence grows when you celebrate not only because you are now a habit-creating machine but also because you are getting better and better at being nice to yourself. You start looking for opportunities to celebrate yourself instead of berating yourself.

A friend once said of my earlier work that I wrote with a signature of “well-founded hope.” The mountains of systematic research, combined with my dedication to drawing insights from the evidence, provided the “well-founded” part. “But the message is always hopeful,” he said. “You demonstrate with evidence that good can become great, that people can build organizations worthy of lasting, that strong values can win in a hypercompetitive world.” Well-founded hope. This study only added to that signature for me. It made me feel even more hopeful and optimistic, not directly about the world at large, but about people. And people, after all, make the world.