Shettima Umara Bulakarima is the first professor of Kanuri language and currently a professor at the Department of Languages and Linguistics, University of Maiduguri. | Tudun Tsira

The secret to a happier workplace? The boss. Harvard professor Arthur Brooks explains why leaders’ emotional health directly shapes culture—and why working on your own happiness is part of the job. Sign up to receive Arthur’s new six-week newsletter, “The Leader’s Happiness Reset" here: hbr.org/HappinessReset | Harvard Business Review