It happens all the time: One of your fellow employees will get angry with another, and words will be exchanged. Or you’ll notice an employee react in a certain way because of fear, or happiness, or surprise, or sadness, or disgust. What you are witnessing is the expression of human emotion and the physical reactions that are the result of those emotions.

Humans have always exhibited physical responses to emotions. In primitive times, these reactions were necessary to preserve one’s life. When a primitive hunter encountered a dangerous animal, his anger or fear either caused him to stand and fight or to retreat to a safe environment. You may have heard this referred to as the “fight or flight” reaction.

Each emotion results in an impulse to act and has a unique role in preparing the body for some type of response. These physical reactions are embedded in our nervous systems and are impossible to avoid. But while these physical reactions meant life or death for primitive humans, today they can clash with rational responses appropriate for the work and social environments.

The Fight Response

One of the strongest emotions people feel is anger, which results in certain physiological responses. When a person is angry, the heart rate increases, and there is a rush of adrenaline that creates a surge of energy for intense action. In addition, when a person is angry, blood flows to the hands. The original purpose was to facilitate grasping a weapon – the “fight” response.

The Flight Response

Closely aligned with anger is fear, which causes the “flight” response. A rush of hormones puts the body on general alert, causing it to freeze temporarily and then making it ready for action. Blood flows away from the face to the large muscles, making it easier to run.

Physiological responses to emotions such as anger and fear enabled primitive humans to concentrate on the threat at hand and decide whether to fight or flight. These physiological responses still occur in humans, even though modern culture doesn’t normally require such actions.

Anger and fear are part of a spectrum of emotions. Other emotions that trigger different physiological responses are surprise, love and happiness, disgust, and sadness. Keep in mind that although people don’t always display their emotions, the underlying physiological reactions are always present.

Physical reactions have been implanted in the nervous system since primitive times. While they originally served as a survival mechanism, in modern society, emotions – and their associated physical and physiological reactions – can obscure rational thinking and cloud judgment.

The next time you see strong emotions exhibited by an individual in your work place or when you experience a strong emotion yourself, keep in mind that the resulting physical reactions are unavoidable – but they are controllable. And by controlling our physical reactions to emotions, we modern humans are able to differentiate ourselves from our primitive ancestors.