DEspite America’s reputation for optimism, nearly three-quarters of U.S. adults are pessimistic about the country’s future. [1] This may not be all bad, though. Decades of research have found that positive thinking isn’t always so positive. In some cases, pessimists fare better than those with a sunnier disposition.

Married couples who were extremely optimistic about their relationship’s future were more likely to experience relationship deterioration. [2] Optimism may also be tied to lower earnings. A study of data from British households found that across two decades, especially optimistic self-employed people earned about 25 percent less than their pessimistic peers. [3] And National Cancer Institute researchers found that people who lowballed their risk of heart disease were more likely to show early signs of it. [4]

Maybe this is because a rosy outlook leaves us overconfident. For example, homeowners who underestimated their chances of radon exposure were less likely to buy radon test kits than were those with a more realistic sense of risk—their optimism left them vulnerable. [5]

Optimism can also beget disappointment. In one study, psychology students were surveyed immediately before and after receiving exam results. Students who had anticipated a higher grade than they received were upset after learning their score; students who had underestimated their grade (i.e., the pessimists) felt better afterward. [6]

Embracing negativity may also have social benefits. Compared with cheery moods, bad moods have been linked to a more effective communication style, and sadness has been linked to less reliance on negative stereotypes. [7, 8] Feeling down can make us behave more fairly, too. People who saw sad video clips before playing an allocation game were more generous with their partners than those who saw happy clips. [9]

So how can you get the most out of a glass-half-empty mind-set? In the 1980s, two University of Michigan researchers described a strategy they called “defensive pessimism,” whereby people harness their anxiety for good. [10] A pair of follow-up studies found that by setting low expectations and envisioning worst-case scenarios, defensive pessimists optimized their performance on a variety of tasks, from darts and math problems to fulfilling real-life goals. [11, 12]

This approach might work across one’s lifetime, too. A 30-year study of more than 10,000 Germans found that older adults who had underestimated their future satisfaction were less likely than their optimistic peers to end up disabled or die prematurely. [13] Defensive pessimism isn’t exactly a new strategy, of course—the Stoics were urging “the premeditation of evils” some 2,300 years ago. Still, it may be time to revise an old maxim: Forget about hoping for the best. Instead, focus on preparing for the worst.

The Studies:

[1] Jones et al., “The Divide Over America’s Future” (Public Religion Research Institute, Oct. 2016)

[2] Neff and Geers, “Optimistic Expectations in Early Marriage” (Journal of Personality and Social Psychology, July 2013)

[3] Dawson et al., “The Power of (Non) Positive Thinking” (Institute for the Study of Labor, July 2015)

[4] Ferrer et al., “Unrealistic Optimism Is Associated With Subclinical Atherosclerosis” (Health Psychology, Nov. 2012)

[5] Weinstein and Lyon, “Mindset, Optimistic Bias About Personal Risk and Health-Protective Behavior” (British Journal of Health Psychology, Nov. 1999)

[6] Sweeny and Shepperd, “The Costs of Optimism and the Benefits of Pessimism” (Emotion, Oct. 2010)

[7] Koch et al., “Can Negative Mood Improve Your Conversation?” (European Journal of Social Psychology, Aug. 2013)

[8] Lambert et al., “Mood and the Correction of Positive Versus Negative Stereotypes” (Journal of Personality and Social Psychology, May 1997)

[9] Forgas and Tan, “Mood Effects on Selfishness Versus Fairness” (Social Cognition, Aug. 2013)

[10] Norem and Cantor, “Defensive Pessimism” (Journal of Personality and Social Psychology, Dec. 1986)

[11] Norem and Illingworth, “Strategy-Dependent Effects of Reflecting on Self and Tasks” (Journal of Personality and Social Psychology, Oct. 1993)

[12] Spencer and Norem, “Reflection and Distraction” (Personality and Social Psychology Bulletin, April 1996)

[13] Lang et al., “Forecasting Life Satisfaction Across Adulthood” (Psychology and Aging, March 2013)