Tool Module: Scientific Research on Emotions

Scientists make a distinction between emotions and feelings.

For scientists, feelings are conscious things. They are what people say they feel. In neurobiological terms, we would say that feelings originate in the cerebral cortex. In this sense, feelings are only one aspect of the emotional process.

Emotions are something broader. They include not only conscious feelings, but also various physiological changes and expressive behaviours. These other aspects of the emotional process originate in various brain structures that are located below the cortex and are much older, from an evolutionary standpoint.

To measure these various physiological changes and expressive behaviours, scientists use various devices. The most commonly measured physiological reactions are changes in heart rate, electrical conductivity of the skin, and body temperature. Some expressive behaviours can also be measured, such as the degree of contraction of certain facial muscles, or reaction times, or performance at a video game.

The voice was long the least studied aspect of emotional expression, mainly because of the technical difficulties involved in encoding and decoding the sound of the human voice. But the advanced capabilities of digital recording have now removed these limitations. Some researchers even believe that we can now decode people’s emotions more accurately from their voices than from their faces!

To analyze the changes that an emotion produces in a subject’s voice, researchers must stimulate the emotion in the subject and get the subject to verbalize at the same time. This is not so easy as you might think. For one thing, the emotions induced in a laboratory are never very intense, so subjects can disengage from them very easily if you ask them to speak a standard sentence at a specific moment. For another, if you tell the subject a story, he or she may express several different emotions simultaneously, which confounds the analysis. This is why some researchers use subterfuge, such as having subjects play voice-activated video games. Video games provide an environment where subjects can utter short responses in a natural way while under the sway of strong emotions.

Facial expressions are an extremely fast, precise tool for communicating emotions. For example, if someone is smiling, you can detect it more than 30 metres away. Or if a friend raises an eyebrow to signal that he has seen you across a crowded room, you can tell, even if this facial movement lasts only a sixth of a second. But the face’s great expressiveness also makes it an ideal tool for deception, so that analyzing it scientifically can sometimes be difficult.

With only 44 muscles, the face is capable of up to 5,000 different expressions. Scientists have determined that real and faked emotions can be distinguished anatomically. For example, when two lovers smile at each other, not only do the muscles on either side of their mouths contract upward, but so do the muscles at the outer corners of their eyes, causing the creases known as “smile lines” or “crow’s feet”. On the other hand, your banker’s polite smile may engage the muscles around the mouth but not those around the eyes.

The earliest humans had to hunt their prey, defend themselves against predators, and raise children who took many years to reach maturity. So their survival very soon came to depend on their ability to quickly decode one another’s emotional states. A number of human expressions are universal, because they are the product of these kinds of biological imperatives. Thus, researchers agree that emotions such as anger, fear, sorrow, disgust, surprise, and joy seem to be etched into the brains of all human beings. That is why, if you showed a photo of an enraged New York City motorist to a Tibetan monk high in the Himalayas, he would immediately know what emotion was involved, and vice versa.