Science writer David Robson’s book The Expectation Effect: How your Mindset Can Change Your World has been making waves. Having studied how the human brain is skewed towards a certain way of thinking, he provides some key insights into how a person’s expectation governs their world;

1. The placebo effect

Our brains are able to predict things and are constantly simulating the world around us and what may happen next. These predictions shape our sensory perception and  it’s not entirely incorrect to say we really do see, hear and feel what we believe.

Using this predictive processing mode our underlying beliefs about ourselves and our situation can often create self-fulfilling prophecies. This phenomenon is known as the expectation effect.

Perhaps the most famous expectation effect is the placebo response, in which positive beliefs about a treatment can relieve patients symptoms and accelerate recovery.

One example of this was a study where patients with chronic back pain were told about the power of expectation to reduce their symptoms before being given a jar of clearly labeled placebo pills, to be taken twice a day.

Over a few days, their symptoms improved by 30 percent. Even more amazingly they still reported benefits five years later, compared to the group who had continued with standard treatment.

The mere knowledge of the expectation effect had helped them mange their pains. Given this doctors are now considering open label placebos as way to stem painkiller addiction.

2. How to turn an unpleasant experience to your advantage

Many of us get stressed when having to face daunting situations, be it a public speaking event, an exam or any other anxiety inducing situation. A racing heart, and sweaty palms aren’t necessarily a bad thing. The stress response is adaptive, the racing heart pumps more oxygen and glucose to the brain helping us think better and hormones like cortisol at moderate levels ensure we remain alert.

3. You are only as fit as you think you are

Many of us have the intention to get fitter, while simultaneously nurturing the belief that we can’t exercising enough. This assumption may be shaping our physiological response to workouts so that we fail to enjoy its benefits.

In general people with positive beliefs about their fitness move their muscles more efficiently, and they are more likely to feel that pleasant lift in mood after a workout.

So the key is to build our mental beliefs around this and remove our pessimistic beliefs. We can then learn to reframe the aches and pains of exercise as signs of progress.

4. Worrying about lack of sleep is actually fueling insomnia

Statistics from the Centre for Disease Control reveals that about 8% of the population has such serious insomnia that they regularly take sleeping pills – an estimated 17 million people.

Despite this, multiple studies also show that our estimation of how much sleep we get, relative to what we need is often highly inaccurate. Many people actually do achieve the seven to eight hours a night they need but believe they are constantly lacking. These “complaining good sleepers” are actually more likely to suffer from poor concentration, fatigue, depression and anxiety than people who sleep less but think they have enough sleep.

These are the “non complaining bad sleepers”. In fact even if you’re a bad sleeper but are positive about it, physical effects of insomnia such a high blood pressure does not manifest as much and is more of an expectation from the complainers.

According to one sleep scientist “worry about sleep is a stronger pathogen than poor sleep”.

5. Your belief about aging determines how long you live

Your beliefs influence how quickly you age. According to the Ohio Longitudinal Study of Aging and Retirement, which examined more than 1,000 participants; “People with more positive views about aging are about half as likely to develop Alzheimer’s.”

Unfortunately our society is full of ageist stereotypes that reinforce the idea that aging is inevitably accompanied by decline.

If you want to fight against it, you might look for positive role models who actively rejected these assumptions. One of them would be Paddy Jones, the world’s oldest acrobatic salsa dancer who began dancing professionally in her 60’s. She now tours the world dancing at 80.