Books like “The Power” and “The Secret” have influenced the increasing popularity of the idea that wishes can be granted through positive thinking and visualization. This mindset has received much criticism for relying on unvalidated scientific claims. Such as the use of quantum physics to explain how the mind works. Critics state that these unvalidated claims promote false hope among readers.

Claims that beliefs single-handedly determine our physical health, financial wealth, and chances of finding love are clearly misguided. But the idea that beliefs have power does have some scientific validity. It just works differently than the authors of these books suggest. Below are three ways that beliefs really can shape reality.
Your beliefs influence your behavior
A basic way beliefs can shape reality is through influence on a person’s behavior. If you believe that you are competent, capable, and deserving of your dream job, you are more likely to seek out and notice opportunities that could help you get there.
You are also more likely to perform well at an interview for that job. Contrary to the common assumption that overconfidence can hurt you, research shows that it may actually be beneficial. Overconfident people appear more socially skilled and higher in social status. This is true even when interviewers have access to objective information about the subject’s actual abilities.
Beliefs can also affect health behaviors. Research shows that people are more likely to start healthy behaviors — like exercising and eating well — if they have a greater sense of self-efficacy (belief in one’s ability to succeed in specific situations or accomplish a task).
But the power of positive thinking has a limit: research also shows that people take better care of their health when they have negative thoughts. For example, when people believe they are in danger of getting a serious illness or risk death. Without awareness of the risks they face, people may lack the motivation necessary to make healthy decisions.
Beliefs about your character can be very powerful. These are beliefs about who you are as a person, on a fundamental level. Research shows that feeling a sense of guilt about doing something wrong can motivate self-improvement. Feelings of shame — that you are a bad person — tend to create a self-fulfilling prophecy. Shame reduces feelings of hope, and undermines efforts to change.
Some evidence suggests that applauding a person’s character rather than their behavior is a more effective means of promoting positive actions. In one study, some children were told they were helpful people for doing something generous. For example, giving away some of their crayons to less-fortunate children. When researchers followed up after the study, the children who were appraised by their character later engaged in more altruistic behavior than the children who only received praise based on their behavior.
Your beliefs influence other people’s behavior
Your beliefs can shape your reality by influencing your own behavior. But they can also influence the behavior or other people, from those close to us to complete strangers. In one study, male subjects were told that a woman with whom they were about to speak on the phone was either unattractive or attractive.
When the recordings were analyzed by outside observers, they concluded that throughout the conversation the male subjects behaved in a more friendly and likable way when they assumed they were talking to an attractive female. This suggests that the participant’s expectations were not only shaped by their own perceptions of their conversation partner. They also adjusted their behavior based on assumptions.
Your beliefs can bring out matching behavior from romantic partners, too. Studies show that people who see their partners in a more idealized view than their partners see themselves tend to be more satisfied with their relationship in the long run. They experience less conflict, and are more likely to stay together. How can this be?
One explanation is that those who idealize their partner have confidence in them, which lessens their partners’ insecurities about the relationship. Partners who feel more secure are more likely to behave in constructive and generous ways, which promotes a higher sense of satisfaction in relationships.
Your beliefs may impact your health
Health and disease are influenced by multiple factors. Many of which are not fully within our control, including genetics, a history of trauma, exposure to environmental toxins, and other circumstances. But research shows that beliefs contribute to health outcomes as well.
In a study of middle-aged adults, those who held more positive beliefs about aging lived an average of 7.6 years longer than those who held more negative beliefs. And in several other studies, optimistic people were found to be less likely to develop heart disease.
Research focusing on the “placebo effect” also backs up the link between health and beliefs. The mere expectation that a treatment will be effective can sometimes make it so. Even if the treatment is just a sugar pill.
How can you control the power of belief to improve your life? One option is to engage in activities that change your habitual way of thinking, like mindfulness, meditation, or keeping a gratitude journal. These things can help you notice and appreciate the good things in life. And can keep you from engaging in negative and destructive thoughts.
Another option is to set a clear purpose for how you want to approach each day, and align your behavior with that purpose. Even when things don’t go as planned, you’ll know that you’re moving in the right direction.
Finally, recognize that while beliefs are powerful, they are not all-powerful. Life is full of suffering that we neither deserve nor invite. Recognizing the limitations of beliefs can make us more empathetic toward those who find themselves in unfortunate circumstances — including ourselves.