When challenges come our way, it may be easy to succumb to negative thoughts. But look on the bright side—optimistic thinking isn't just in our heads. Thinking positively can also boost our physical and mental health.Personality and quality of life: the importance of optimism and goal adjustment. Wrosch C, Scheier MF. Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation, 2003, Jul.;12 Suppl 1():0962-9343.

The Power of Positive: The Need-to-Know

Optimistic thinkers tend to anticipate the best possible outcome in any situation. (For instance: "I may have totaled my car, but thank goodness for insurance!") And research suggests seeing the glass half-full is good for our health, career, and love life. Studies have found self-reported optimism predicts lower rates of mortality and cancer, and better cardiovascular health and immune function.Optimism and physical health: a meta-analytic review. Rasmussen HN, Scheier MF, Greenhouse JB. Annals of behavioral medicine : a publication of the Society of Behavioral Medicine, 2009, Aug.;37(3):1532-4796.Optimism-pessimism assessed in the 1960s and self-reported health status 30 years later. Maruta T, Colligan RC, Malinchoc M. Mayo Clinic proceedings, 2002, Aug.;77(8):0025-6196. Other research has found the benefits of positive thinking are especially pronounced in low-income countries.Is the emotion-health connection a "first-world problem"? Pressman SD, Gallagher MW, Lopez SJ. Psychological science, 2013, Feb.;24(4):1467-9280. One study even suggests optimism helps women battle breast cancer.Breast cancer, psychological distress and life events among young women. Peled R, Carmil D, Siboni-Samocha O. BMC cancer, 2008, Aug.;8():1471-2407. And elderly people who hold positive stereotypes about old age generally recover better from disability than those who think negatively.Association between positive age stereotypes and recovery from disability in older persons. Levy BR, Slade MD, Murphy TE. JAMA, 2012, Nov.;308(19):1538-3598.

Some psychologists think optimists tend to be healthier because they cope better when they can't meet their goals.Personality and quality of life: the importance of optimism and goal adjustment. Wrosch C, Scheier MF. Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation, 2003, Jul.;12 Suppl 1():0962-9343. It's also possible that people who think positively attribute less significance to stressful events.Can positive thinking help? Positive automatic thoughts as moderators of the stress-meaning relationship. Boyraz G, Lightsey OR. The American journal of orthopsychiatry, 2012, Aug.;82(2):1939-0025.

But the benefits of optimism go beyond a clean bill of health. Forget the raving resume—there may be a connection between positive thinking and landing a stellar job. Optimists also have a better chance of securing a stable, loving relationship.Optimism: an enduring resource for romantic relationships. Assad KK, Donnellan MB, Conger RD. Journal of personality and social psychology, 2007, Oct.;93(2):0022-3514. Still, thinking positively may be easier said than done.

Man Climbing Mountain Every Little Thing Is Gonna Be All Right: Your Action Plan

While some psychologists think we can learn to be optimists, other experts believe optimism is a personality trait we're born with. And other factors, like socioeconomic status and cultural background, may have a role in our ability to think positively. Several studies have found a relationship between pessimism and lower economic status—though it's unclear whether low socioeconomic status causes people to be more pessimistic or it's other way around.Socioeconomic disparities in optimism and pessimism. Robb KA, Simon AE, Wardle J. International journal of behavioral medicine, 2010, Mar.;16(4):1532-7558.Socioeconomic status in childhood and adulthood: associations with dispositional optimism and pessimism over a 21-year follow-up. Heinonen K, Räikkönen K, Matthews KA. Journal of personality, 2006, Dec.;74(4):0022-3506. Cultural differences may also come into play. Studies suggest Western cultures tend to anticipate more positive events than Eastern cultures do. Some psychologists suggest that's because Westerners focus more on self-enhancement and see themselves more positively than Easterners.Cultural variations on optimistic and pessimistic bias for self versus a sibling: is there evidence for self-enhancement in the west and for self-criticism in the east when the referent group is specified? Chang EC, Asakawa K. Journal of personality and social psychology, 2003, Jul.;84(3):0022-3514.

But before becoming Mr. or Ms. "Everything-Is-Awesome," know that being too optimistic can have a downside.The costs of optimism and the benefits of pessimism. Sweeny K, Shepperd JA. Emotion (Washington, D.C.), 2011, Feb.;10(5):1931-1516. Expecting the best in every situation may lead to failed expectations. Some experts argue defensive pessimism—"hope for the best, prepare for the worst"—helps people respond to certain threats and may even reduce anxiety.A two-factor model of defensive pessimism and its relations with achievement motives. Lim L. The Journal of psychology, 2009, Jul.;143(3):0022-3980.

Here are some quick tips on how to start seeing the glass half-full:

  • Find the good. Even in less-than-great situations, there's a way to find something positive. It may be hard to see at first, but try looking closer! (For instance: "I may be completely lost, but the view from here sure is pretty.")
  • Write it down. At the end of the day, write down a few good things that happened, like finishing a big report at work or getting an email from an old friend. The habit makes it easier to appreciate the positive parts of life.
  • Speak with success. Sometimes it's not the specific situation that determines a good or bad mood, but how we talk about it. (For example: "The exam may have been super hard, but telling friends we tried our best may cheer us up.")
  • Forget the green-eyed monster. It's easy to compare ourselves to others and become envious of what you don't have. Instead, try to appreciate the good qualities and remember what you're grateful for.
  • Take control: Science has shown people feel more optimistic about situations they can control.Is optimistic bias influenced by control or delay? Kos JM, Clarke VA. Health education research, 2001, Dec.;16(5):0268-1153. So take a seat behind the driver's wheel and remember choices like working out more and eating healthfully are (almost always) yours!
  • Stay balanced. Life isn't all good, all the time, so don't worry if those positive thoughts don’t flow freely. Staying realistic is also important to help manage anxiety and boost productivity.

Originally published in September 2013. Updated June 2015.

READ THIS NEXT: 40 Ways to Relax in 5 Minutes or Less