Leave the Lights On: How Joyful Decisions Can Save Our Species

Jiaying Zhao, Ph.D. ("JA-ying JOW") is a behavioral scientist who studies why people fail to act on the problems they care about most, and what it takes to change that. "My vision is to create a world where we won't have environmental crises or poverty," she says.

Her work travels well beyond the lab. Zhao has worked with NASA, NOAA and the US and Canadian Forest Services to build pathways to net zero and zero waste, and has advised dozens of governments, NGOs and businesses, including the UN Sustainable Development Solutions Network, the US Social and Behavioral Sciences Team, the UK Commonwealth Secretariat and the Privy Council Office of Canada. She has testified as an expert witness in the Canadian Parliament and meets weekly with senators and policymakers to inform public policy on climate change and poverty reduction.

"If you have happy employees, you're going to have less turnover and you're going to have more productive, committed workers," says Elizabeth Dunn, one of the world's leading happiness researchers. Dunn runs the Social Cognition and Emotion Lab, affectionately called "The Happy Lab," where her research focuses on how to optimize scarce resources such as time, money and technology to enhance happiness in life and at work.

Her research shows that giving away as little as $5 can spark satisfaction: "When people use money to benefit others, they actually get the biggest return on investment in terms of the happiness gained." She is co-author of Happy Money: The Science of Happier Spending, which distills five principles for getting more happiness from money, helping companies create happier employees and offer happier products to their customers.