Skip the holiday turkey or the $25 gift certificate. This year, give a gift to your employees that will have a lasting impact on how they treat each other.

Give everyone a book of etiquette.

I’m serious. Make them read it, too. Reviving the lost rules of proper conduct could go a long way in reducing workplace misconduct of all kinds—including sexual harassment (the list is growing every day), other harassment and discrimination, bullying, rudeness, and personality conflicts. Recently, good behavior and civil discourse seem to have sunk to an all-time low. An etiquette book might help reverse the trend.

In 2013, the Harvard Business Review published an article on the “Price of Civility,” which confirms our own empirical evidence about the high and yet often hidden costs of workplace incivility. The research details the alarmingly high percentage of workers who respond to incivility by decreasing their time, effort, and quality of work.

One of the article’s authors has since published what has become one of my favorite guidebooks for workplace conduct: “Mastering Civility: a Manifesto for the Workplace” (2016). The book includes quizzes to help us assess whether we are civil to others, and why civility is a business imperative.

These concepts aren’t new. In the 1920s, Emily Post’s book on etiquette noted the importance of ethics and manners in business. In an updated version, “The Etiquette Advantage in Business” (2005), the author notes: “Your own behavior on the job influences the way others act in the workplace.” She also offers practical guidance on “How to Say No” to an office mate’s romantic overtures, appropriate dress, and communicating with coworkers.

Perhaps there was a time when we just knew how to treat each other with respect and dignity. It is time we were reminded.