The shower murder scene in Alfred Hitchcock’s Psycho never fails to give me goosebumps. The ominous music by composer Bernard Herrmann, the eerie silence just before the murder, and Norman Bates’s Dark silhouette all create thrilling suspense.
Besides being a cinematic masterpiece and a pop-culture cornerstone, what makes that particular scene so effective at inducing goosebump? Or, for that matter, when one listens to a glorious piece of music? ‘I got the goosebumps’, the music show judges often affirm after an impressive act.
We get goosebumps when we feel cold. What’s going on here?
What Are Goosebumps and Why Do We Get Them?
Scientifically called piloerection, goosebumps are tiny elevations of the skin at the base of the hair. The name comes from the uncanny resemblance the goosebumped hairless human skin has to a plucked goose (or any other bird). This prickling result isn’t a uniquely human trait. Many other mammals have goosebumps.
Goosebumps are caused when stress (cold temperature, perceived threat, intense emotions etc.) is experienced by our brain. In these moments, the nervous system sends message to nerve endings that trigger the arrector pili muscles, which cause goosebumps to appear.
Piloerection is a thermoregulatory mechanism, i.e., a way to control body temperature during cold temperatures. The hypothalamus receives signals that the outside temperature is cooler than the body likes it. It then activates the sympathetic nervous system, which tells the arrector pili muscles to contract, raising the hair upright.
In furry animals, raised hair creates a warm blanket keeping the cold out. The hairs trap air between them creating insulation. This keeps the body heat in while keeping the cold. This doesn’t work as well in humans because of our lack of hair. It just serves as a reminder that one is indeed cold.
Fear and awe
The other, and arguably, more fascinating scenario that causes goosebumps is fear. This is the category that gives me goosebumps while watching Psycho. Here, perception of fear and its override by other brain regions and pathways plays a large role. In mammals other than humans, fear is the direct player.
A cat when threatened raises its body hair, arches its back, bares its teeth and hisses. This is the brain’s response to fear. The amygdala, a small almond-shaped part of the brain that controls emotions, especially fear and aggression, finds out that there is a scary stimulus (maybe a human trying to pet it).
It will instruct the hypothalamus through a pathway called the ‘punishment circuit’. These punishment parts of the brain, especially the periventricular zone of the hypothalamus, then awaken the fight and flight response, leading to piloerection.
Note that there is an overlap between systems involved in fear and in thermoregulation. But here the goal isn’t to keep warm. It is, instead, to warn. With fur raised, the cat looks bigger and more menacing. It sends the message to the threat, “I am dangerous. Stay away or I will harm you.”
Though humans don’t have much use for that (we have created multiple ways of appearing like a threat), the system remains. Watching a horror film triggers the same systems in us as it does in a cat. But, humans have a reasoning capability that knows that Norman Bates cannot climb out of the TV screen and kill you.
This overrides the older, more primitive brain regions (the limbic system) so we don’t run out of the house or theatre screaming. A good horror film or any other creepy situation will be able to trick the newer shiner parts, holding us and our brains in the fear. They make us feel like we’re a part of the movie.
Getting the “chills” while consuming art, especially music, is such a perplexing phenomenon that it even has a special name – frisson. Frisson is a set of physiological changes that happen to one’s body upon hearing or watching something that emotionally stimulates them.
Piloerection in this scenario is also triggered by sympathetic nerves stimulation. What emotional circuitry causes that stimulation is still hazy. Chills-inducing music activates the reward circuit of the brain, multiple lines of research have found.
There is also an accompanying dopamine flood (a neurotransmitter linked with the reward neurocircuitry) in areas like the nucleus accumbens which is part of the reward system of the brain.
Are Goosebumps useful to us?
Antonio Damasio’s book Descartes’ Error encouraged a dualist approach to emotions – the body informs our emotional state as much as the brain. Anxiety is characterised by rapid heart rate and shallow breathing. These physiological responses are part of what inform us of our feelings of anxiety.
Piloerection, as functionless as it might seem on the surface, might play a role in informing and reinforcing our emotions of fear or awe. A 2012 study found that on artificially stimulating piloerection in participants consuming an entertainment medium, participants reported feeling a higher sense of emotion and surprise.
This means that getting the goosebumps might reinforce in your mind that you really like this piece of art. The study also implies that getting goosebumps when externally stimulated, might invoke certain emotions that one might not have had for an art piece.
Measuring goosebumps could also be a metric for scientists studying emotion. Neuroscientists already use something called skin conductance, to study certain emotional changes. Skin conductance is a change in the electrical properties of the skin.
Though one can’t feel like skin getting more or less electric when they are sad or happy, scientists do measure these minute changes.
Goosebumps one of those scientific mysteries, like crying or sneezing. They might or might not be helpful to us, but they keep other animals safe and warm. So, the next time you get the chills from listening to your favourite piece of music or getting goosebumps from watching the latest horror pick, you’ll know what causes them.