Imagine swimming in a lake on a hot summer day. The water is quite warm, but the wind is strong and the moment you leave the water you feel chilly and get “goosebumps (鸡皮疙瘩) ”. So you change clothes and move inside to warm up. You make a nice cup of tea, get under a blanket and turn on the radio. Suddenly, you hear a song from a long time ago, one that your grandmother often sang to you when you were a child. 【小题1】 Why do such seemingly unrelated events lead to the same bodily reaction?

Goosebumps are a physiological phenomenon we got from our animal ancestors. They are tiny elevations of the skin that look like the skin of children or geese after the feathers have been pulled off. 【小题2】

Goosebumps are caused by a contraction (收缩) of muscles that are attached to each hair. Each contracting muscle creates a shallow depression (凹陷) on the skin surface. As a result, the surrounding area stands out. 【小题3】 In animals with a thick coat of hair this rising of the hair expands the layer of air. The thicker the layer of hair, the more heat is retained. In people this reaction is useless because we do not have a coat of hair on our bodies.

In addition to cold, the hair will also stand up in many animals when they feel threatened. 【小题4】 This will probably make the attacker back off. People also tend to experience goosebumps during emotional situations, such as walking down the aisle during their wedding, listening to their nation’s anthem, or even just watching horror movies. Quite often a person may get goosebumps many years after a significant event, just by thinking about the emotions they were experiencing at that time.

The reason for all these responses is the subconscious release of adrenaline (肾上腺素). It is often released when we feel cold or afraid, but also if we are under stress and feel strong emotions. Other signs of adrenaline release include sweaty palms, an increase in blood pressure, a racing heart or the feeling of “butterflies” in the stomach.