Evidence for the importance of emotions comes from the field of psychology, too. Here are some important findings:

Stress activates a certain gene that attaches to brain DNA, causing abnormalities that lead to depression as well as other emotional difficulties. The first bad experience feels negative and sets up a pathway in the brain. The second experience feels worse, and after repeated experiences, the memory trace has become a superhighway for depression.

When we are calmly energized (good stress), the brain secretes catecholamines, adrenaline, and noradrenaline. This kind of "stress" is beneficial because we can perform at our best.

When stress is severe, the brain secretes cortisol, which intensifies sensory awareness but dulls rational thinking. When levels of this substance are high, our memory does not work well, and we make more mistakes. Cortisol, levels rise when we are bored, frustrated, or highly anxious, or when we have other strong negative emotions.

Prolonged stress in laboratory animals has been shown to actually destroy neurons, shrinking the brain's memory center.

Experiments were performed in which people were shown shapes at a rate too quick for the shapes to register with the thinking brain. But subjects developed a preference for those shapes, even though they had no conscious awareness that they had seen them. The limbic brain perceives things more quickly, and even decides if it likes those things before the thinking brain can be engaged.

When we look at angry or happy faces, our facial muscles change very subtly in the direction of what was viewed. These subtle changes, while not visible to our eyes, can be measured with electronic sensors.

People showing little emotion when they first sit down to face an individual who shows a lot of emotion invariably pick up on the mood of the expressive partner. We subtly re-create in ourselves the mood of another, and may, in fact, be programmed to do so.

Animal studies show that primates experience empathy, just as humans do. When an animal sees another of its species in distress, the primate brain has specialized neurons in the visual cortex and in the amygdala that fire only in response to particular facial expressions that convey fear, threat, or submission. This might indicate that humans also have such specialized "empathy" neurons, and that empathy is programmed into our brains.

These findings are particularly relevant in the workplace, where stress can affect the environment as well as performance. Humans are complex "wholes," programmed to respond emotionally. No one can perform their jobs apart from their emotions, but excess stress is particularly disruptive to smooth functioning, and it makes concentrated, rational thinking very difficult. "Emotionally intelligent" individuals harness these emotions and use them appropriately.

The medical laboratory also provides us with clues about how emotions operate in our brains and bodies. Consider these examples:

Some years ago the accepted "cure" for mental illness was to do a prefrontal lobotomy (removal of a section of the brain that connects the emotional and cognitive brains). The procedure worked in that severe emotional distress was indeed relieved, but the severing of the circuitry destroyed the patient's emotional life, as well. With no ability to feel or express emotion, these patients appeared dull and lifeless.

If the limbic brain is injured or surgically removed due to disease, the individual will lose emotional memory, and lose all feelings. He or she will have no capacity for relationships and, in fact, will not be able to remember friends and relatives. They won't be able to make even simple decisions because they no longer have any memory of likes and dislikes.

The removal of the amygdala in animals causes them to lose fear, rage, and the urge to cooperate or to compete. This is a strong indication that the amygdala, a part of the emotional brain, controls our passions.

Biofeedback is effective in controlling certain chronic diseases. This merging of the first brain, the limbic brain, and the thinking brain results in measurable changes at the cellular level, and improves the functions of bodily systems.

Our rational minds give us information about people and things, yet preferences and why we have them are based on the limbic brain's storage of emotions. Without access to that information, we are unable to make even the simplest of decisions because all choices are equal. Emotions are always present in our lives, whether we recognize them or not.

The Case for an Emotional Brain
Emotions are not just a matter of the heart. Recent advances in research have shown that they are also a result of brain biochemistry. These conclusions come from neuroscience, evolution, medicine, psychology, and management. Emotional signals in the brain are felt throughout the body — in the gut, in the heart, in the head, in the neck, and so on. These sensations are important signals: If we learn to read them, they will help us make decisions and initiate action.

Most scientists believe that the control center of emotions in the brain is the limbic system, consisting of the amygdala, the hippocampus, and other structures in the mid-brain. The limbic system stores every experience we have from the first moments of life: impressions are stored in these areas long before we acquire the verbal or higher thinking abilities to put them into words. It is this vast warehouse of feelings and impressions that provides a context or meaning for those memories.

Messages are transmitted to the brain by neurons, traveling through an electrical transmission system. In the 1970s, however, scientists discovered that our bodies also contain a chemical system for transmitting messages. This system is based on chemicals called peptides, which have receptors in every cell of our bodies. These highly sensitive information substances are thought to be the chemical substrates of emotion, triggering impression memories throughout our lives. Our brains are linked to all our body systems, and it is these peptides that are responsible for the emotions we "feel" in various parts of our bodies.

This chemical transmission system just described is far, far older in evolutionary history than the electrical brain. In fact, many of the same information substances found in humans are found in one-celled animals. Their presence in the most basic as well as the most complex forms of life is a clear indication of their importance.