How does Surprise affect your Body

Surprise, an instinctive emotion, is a reaction to an unexpected event or sound or a deviation from the norm. It can be pleasant or unpleasant and range in intensity. 

Of the seven instinctive emotions, surprise is the shortest feeling. For a fleeting moment, you experience something that you do not remember or expect. In the case of an unexpected sensory experience, like a sound, you feel startled, your body reacts. In surprise, positive or negative, your body freezes for milliseconds, your heart rate slows down, your blood pressure increases, your pupils dilate and the bilateral inferior frontal gyrus and bilateral hippocampus parts of the brain are activated. Surprise intensifies the subsequent emotions, from joy to fear and can trigger the ‘fight or flight’ instinctive reaction. 

Back in 350 BC, Aristotle, a Greek philosopher, recorded the feeling of surprise. Confucius, an ancient Chinese philosopher, born in 551BC, included surprise as one of the seven universal emotions, in his book of Rites. In more modern times, Darwin discussed surprise in terms of biological function, a theory further developed by evolutionary emotion theorists Silvan Tomkins and Carroll Izard. It is thought that the purpose of surprise is to focus attention, both in mind and body, to assess the situation.

Your body freezes in surprise 

Scientific studies, Dutra, Waller, & Wessel, 2018 over the last decade, have shown that your body freezes for milliseconds when surprised. A more recent study, conducted in Columbia University in 2019, shows that a rapid release of the hormone serotonin into the nervous system may be the biological brain mechanism for how your body freezes. The study was conducted by manipulating levels of serotonin and dopamine on the ventral nerve cord (VNC) of fruit flies, which is similar to the human spinal cord. 

Surprise can make you jump

When strongly surprised, by a loud noise or something completely out of your norm, your body freezes for milliseconds and  then your body jumps. This is caused by your instinctive  ‘fight or flight’ modus. Thus, in English, the expression ‘jump from surprise’ is used.

Sensory surprises affect your body more  – the startle effect. 

When surprised through a sensory experience like a gun shot or an unexpected tap on the back, in most cases, your body has a bigger reflex reaction. The degree to which you will react will depend on the intensity of the input. In some scientific studies on emotion, the startle reaction and the surprise reaction are considered to be different whereas in ordinary language these are interchangeable. Common sense and human experience indicates that when the element of surprise is extremely intense. for example, an unexpected death, your body can react.

Surprise! What happens next depends on you

Not all surprises are negative but not everybody likes a surprise that was meant to be positive. All surprises, negative or positive create the same millisecond of freezing effect on your body and thoughts but as you take in the information, your ensuing body reaction can be that of joy/happiness or fear/anger. A surprise party or an adventure designed to surprise you can be a positive experience but for others a negative experience.  For some people, a surprise can be quite unhealthy, for example if they have a weak heart or high blood pressure. 

Your heart rate lowers in a state of surprise 

When you are surprised, your heart rate slows down. A study(Aug 2021) by Marret K Noordewier Daan et al published in ‘Biological Psychology’ looking at the physiological effects of surprise, proved that your heart rate is slower, during the state of surprise and for a few seconds after surprise. 

Your blood pressure increases in a state of surprise 

The same study by Marret K Noordewier Daan et al, that analysed heart rate, also revealed that your systolic and diastoloic blood pressure increases. In the case of negative surprises, the results revealed that systolic blood pressure increased for longer. 

Surprise intensifies your emotions

Whether the surprise has caused you joy/happiness or anger/fear  the intensity with which you feel the following emotion  in your body is much more intense.

Your pupils dilate with surprise 

That classic cartoon image of eyes popping out in surprise is scientifically true for everybody. Your pupils dilate when you are surprised, according to a study by Preuschoff k et al. affiliate to Zurich University and published in Front Neurosci. According to the study, there were no variations in individuals. 

Instinctive emotions are like the weather, beyond your conscious control. For an  balanced life, the first step is to understand human instinctive emotions, how they work and practical steps to take in order to avoid situations that are destructive to emotional wellbeing. Surprise can be as short as a flash of lightning and the ensuing reaction can give you a rush of pleasure or fright. Emotional evolutionary theory suggests that surprise has evolved to help drive learning in humankind.