Basic Emotions: What Is Surprise?

There is still no consensus among scientists regarding the psychological definition of surprise. Some researchers view it as a cognitive assessment based on the probability of an event, while others consider surprise to be one of the basic emotions due to its unique facial expression. If surprise is an emotion, it is quite unusual: it can be both positive and negative (whereas other emotions are typically either one or the other, but not both), and it significantly influences the experience of other emotions.

The concept of surprise is relevant to many aspects of human behavior. People notice unexpected events and focus on them; surprise encourages curiosity and learning. It is also a key factor in our emotional lives. Neurological studies show that when monkeys expect a reward, their dopamine neurons are activated, and when they finally receive the reward, the activation of these neurons directly depends on their prior expectations. The conclusion: unexpected rewards lead to greater excitement, so unexpected pleasures are stronger than expected ones. Thus, the experience of surprise depends on the importance of the outcome and our expectations about it.

How Long Does Surprise Last?

Surprise is the most fleeting of all emotions, lasting no more than a few seconds. Some other emotions can also be brief (like fear), but the difference is that, under certain conditions, they can last much longer, whereas surprise always has a fixed and limited duration.

The main function of surprise is to focus our attention so we can most effectively determine what is happening and whether we are in danger. Surprise appears quickly, is experienced quickly, and passes within seconds, right after we realize what is going on. After that, surprise can turn into fear, amusement, relief, anger, disgust, and so on, depending on what surprised us. Additionally, surprise may be followed by a complete lack of emotion if we decide that the surprising event is actually insignificant to us.

What Surprises Us?

Universal triggers for surprise are sudden and unexpected events, such as:

• Loud noises (for example, the sound of your car tire bursting);
• Unexpected movements (like someone throwing a ball at you without warning).

But if surprise depends on sudden and unexpected events, what makes an event unexpected? It’s simple: an unexpected event is one with a low probability, but each person’s understanding of probability can vary greatly.

Unexpectedness depends on how easily a person can imagine a particular event. For example, some people will be more surprised to randomly draw a red ball from an urn containing 20 balls, only one of which is red, than to draw the same red ball from an urn with 200 balls, 10 of which are red. This makes sense: although both events are equally probable, the first can happen in only one way, while the second can happen in 10 different ways. Unexpectedness also depends on the ability to imagine different possible outcomes. For instance, an unexpected negative event often feels more surprising and tragic if a person realizes it could have been avoided in several different ways, compared to a situation where there was only one possible outcome.

Finally, the degree and understanding of unexpectedness depend on social and cultural norms: people learn to react to events from their social environment. For example, studies show that people in East Asia tend to accept contradictions and inconsistencies as normal and are less surprised by most events than people from Western cultures.

Startle, Fear, or Surprise?

Many people tend to confuse these three states because their expressions are very similar. However, while surprise is an emotion, startle is a physical reflex, and that is their main difference. The startle response is even more limited in time than surprise: the expression of startle becomes apparent within ¼ of a second and ends within ½ a second. If you are warned about a surprise in advance, you can avoid being surprised, but you cannot suppress the startle reflex.

The facial expression of startle is also the direct opposite of surprise. A sudden startle makes us withdraw from what’s happening—we squeeze our eyes shut tightly, our eyebrows are lowered, and our lips are tense. In contrast, with surprise, our eyes open wide, our eyebrows are raised, and our mouth opens slightly to take a quick, sharp breath. At the same time, the body activates attention mechanisms, you might move your head or raise your hands to protect your face, and you may reflexively step back from the source of surprise.

As for the relationship between fear and surprise—these are the two emotions whose facial expressions are most often confused, because they share the same key features. However, while both surprise and fear involve raised eyebrows, with surprise the eyebrows are arched higher, and the upper eyelids and jaw are more relaxed.