Expectation plays a large role in our society today. Standards projected onto us are one of the most influential factors regarding how we choose to act and present ourselves. It can force us to abandon our former selves and dictate our behavior, as shown in the Stanford Prison Experiment. The study had 24 male subjects of similar race and backgrounds, all of whom were judged to be the most mentally and emotionally stable. They were put in a mock prison environment, where 12 of them were randomly appointed as "guards", and the other 12 were "prisoners".
Almost immediately, the guards began to show an embedded streak of sadism, going out of their way to humiliate and punish the prisoners, whom just days earlier were considered their peers. Physical punishment and forced exercise were commonly used by the guards to assert their authority over the prisoners, who adapted to their roles. Guards also stripped prisoners of their basic human rights, confiscating their mattresses and denying them access to the bathroom. After the study, all the subjects reverted back to their previous, stable selves. When asked about their behavior, many of the guards and prisoners indicated that they were only acting out roles that they thought were expected of them.
Expectations can have the overwhelming power to essentially change a person's identity. It can manipulate our mindsets and behaviors. But, often times we find ourselves affected by the expectations that we ourselves have formed. As people, we have a natural eagerness to make sense of our world- what poet Wallace Stevens called our 'rage for order'- we are prone to perceive patterns. When forming expectations, we are simply trying to reduce the randomness by connecting ideas in a way that brings order to our lives. For example, when we hear someone say a certain movie is good, we walk in the theater with that in mind. When we know what to expect, that sense of uncertainty goes away, bringing an element of stability and order. It is a way to adapt and make sense of the world.
Yet, we are often fooled by these expectations and their smaller, subtler effects on our everyday lives. A common phenomenon that does this is the placebo effect. The placebo effect occurs when a subject is given a placebo (i.e. a fake treatment, such as a sugar pill) with the belief that it is an active treatment, and finds his or her conditions improving. The mere expectation of recovery can manipulate one's body into actually recovering faster, to the point where a placebo can give the same amount of relief as over six milligrams of morphine. A separate study found that when changing the price of wine samples, volunteers preferred the taste of the "most expensive" wine, even though they all came from the same bottle. Brain scans later revealed that expectations about a wine's taste due to its price actually changed the level of activity in the brain's pleasure center.
Of course, our expectations can only "trick" us to a certain extent. Placebos are not magic potions. They don’t make blind people see. If you are paralyzed, they won’t help you walk. Likewise, a high price tag can't fool someone into drinking a glass of spoiled wine. However, simply being aware of our expectations can make a big difference.
The main reason we get fooled by our expectations is because as people, we like to be right. Being right reinforces our expectations, which in turn, reinforces that sense of order we try to achieve with them. This works out most of the time because usually, our expectations are right. Medicine helps us heal faster, expensive wines taste better, and good movies get good reviews. The trouble is when we are not right, which happens more often than we are aware of. This is because we tend to be blinded by confirmation bias. Confirmation bias is the inclination to look for information that supports our preconceptions and to ignore or distort contradictory evidence. In other words, we may be wrong, but we don’t like to admit that. We don’t even see it because we’re too busy looking for evidence to confirm our previous ideas. 
Although confirmation bias makes us feel better, it blurs the line between reality and perception, which results in us being fooled by our own minds. The key to overcoming confirmation bias is the ability to look the other way and think backwards. Instead of looking for how things are the same, we can look for how they are different. Instead of seeking evidence to confirm our perspectives, we can seek to shake them up. Instead of wanting to be right, we can want to be wrong. In other words, take the time to consider the flaws of a movie before automatically deeming it a masterpiece just because you expected it to be one. Ask how things have changed over time, and why that may mean your expectations are inaccurate. Learn to be aware of the conflicting nature between reality and perception to get a better sense of them both.
Although it's not vital to our survival, it's worth being aware of the connections between what we think and what we experience to gain a broader sense of the world and perhaps embrace that randomness we once struggled to comprehend.