In the years since then, scientists have refined the exact components of “powerful” language. But at its core, the main idea remains the same. Speaking with power makes people seem confident. It makes them seem more certain, self-assured, and knowledgeable, which makes audiences more likely to listen and change their minds.

But in this context, it turned out that the exact opposite occurred. Expressing doubt about a contentious issue actually increased persuasion. Particularly among people who already had strong beliefs, hearing someone else wasn’t sure about their opinion encouraged them to change their mind in that direction.

Using similar language can facilitate conversation, make people feel connected, and increase their perception that they are part of the same tribe. All of which can increase liking, trust, and a variety of positive downstream outcomes.

But those two or three words made a big difference. Rather than hurting their motivation, praising the students’ process, or how hard they had worked, encouraged them to keep going.

Behavioral scientists have conducted hundreds of studies about the differences between powerful and powerless words and phrases. We are especially smitten with research led by Jonah Berger at the University of Pennsylvania and by our Stanford colleague Jennifer Aaker. We draw mostly on their work to generate five tips about the kind of talk that provokes people to act, persist, and develop imaginative solutions.