I think few would be surprised to learn that J. K. Rowling’s Harry Potter titles are the best-selling children’s books of all time, but do you know which works take second place in that category? It’s the Goosebumps series by R. L. Stine.
From 1992 to 1997, Stine wrote and published 62 Goosebumps books. To date, these books have been printed in over 3o languages, with over 400 million copies sold worldwide (this does not include Stine’s numerous spin-off books) and adapted for television and film. Each book in the Goosebumps lineup features different child characters who find themselves in scary situations that often involve encounters with the bizarre and supernatural.
The title of the series is apropos. Humans get goosebumps whenever we are afraid. We also get goosebumps when we are moved by something beautiful and awe-inspiring. And, of course, we get goosebumps when we are cold.
Goosebumps are caused by a process dubbed piloerection. When we feel cold, tiny smooth muscles (called the arrector pili) deep within our skin contract. Because these muscles are attached to hair follicles, this contraction causes our hairs to stand on end. Getting goosebumps is one of our quirks as human beings. Most biologists don’t think this phenomenon serves any useful purpose, making it that much more of an oddity. So, if goosebumps have no obvious utility, then why do we experience them at all?
Evolutionary Explanation for Goosebumps
Many life scientists view goosebumps as a vestige of our evolutionary history. So, while goosebumps serve no apparent function in modern humans, evolutionary biologists believe they did have utility for our evolutionary ancestors, who were covered with a lot of hair. Presumably, when our ancestors were cold, the contraction of the arrector pili muscles created pockets of air near the surface of the skin when the hairs stood on end, serving as insulation from the chill. And when our ancestors were frightened, contraction of the arrector pili muscles caused their hair to puff up, making them seem larger and more menacing.
These two behaviors are observed in other mammals and even in some bird species. For evolutionary biologists, this shared behavior attests to our evolutionary connection to animal life.
In other words, many life scientists see goosebumps as compelling evidence that human beings have an evolutionary origin because: (1) goosebumps serve no useful purpose in humans today and (2) the same physiological process that causes goosebumps in humans causes hair and fur of other animals to stand erect when they feel cold or threatened.
So, one theological question creationists need to address is this: Why would God create human beings to have a useless response to the cold or to being frightened? For those of us who hold to a creation model/design perspective, goosebumps in humans cause us a bit of a fright. But is there any reason to be scared?
What if goosebumps in humans serve a useful function? If they do, that function undermines the idea that goosebumps are a vestige of our evolutionary history and, at the same time, makes it reasonable to think that human beings are the handiwork of a Creator. Accordingly, all facets of our anatomy and physiology are intentionally designed for a purpose, including goosebumps. And this is precisely what a research team from Harvard University has discovered. These investigators identified an unexpected function performed by arrector pili muscles, beyond causing hairs to stand erect.1 This new insight suggests a reason why humans get goosebumps, making it reasonable to interpret this physiological feature of human beings within a creation model/design framework.
Multiple Roles of the Arrector Pili Muscle
To carry out its function, the arrector pili muscle forms an intimate association with nerves in the sympathetic nervous system. This component of the nervous system contributes to homeostasis, allowing the bodies of animals (including humans) to maintain constant and optimal conditions. As part of this activity, animals receive sensory input from their surroundings and respond to environmental changes. So, in this case, when a mammal experiences cold the sympathetic nervous system transmits the sensation to the arrector pili muscles, causing them to contract, helping the animal to stay warm.
Recently, the Harvard research team, working with mice, discovered that the arrector pili muscle also plays a structural role, with the individual nerve fibers of the sympathetic nervous system wrapping around the muscle. This architecture positions the nerves next to a bed of stem cells near hair follicles, providing the sympathetic nervous system with a direct connection to the hair follicle stem cells.
Normally, the hair follicle stem cells are in a quiescent (inactive) state. Under conditions of prolonged cold, however, the sympathetic nerves release the neurotransmitter norepinephrine. This release stimulates the stem cells to replicate and develop into new hair. In other words, the interplay between the arrector pili and the sympathetic nerves provides both a short-term (contraction of the arrector pili) and a long-term (hair growth) response to cold.
The researchers discovered that when they removed the arrector pili muscles the sympathetic nerves retracted, losing their connection to the hair follicle stem cells. In the retracted state, the sympathetic nerves could not stimulate the activity of the hair follicle stem cells. In short, the arrector pili plays an integral role in coupling stem cell regeneration and, hence, hair growth to changes in the environment by functioning as scaffolding.
Goosebumps and the Case for Creation
In mammals (which have a coat of fur or bodies heavily covered with hair), the dual role played by the arrector pili muscles in mounting both rapid and long-term responses to the cold highlights the elegance, sophistication, and ingenuity of biological systems—features befitting the work of a Creator. But does this insight have any bearing on why humans experience goosebumps if they are created by God?
Toward this end, if the arrector pili muscles served no true function, evolutionary theory predicts that they should atrophy, maybe even disappear. Yet, the work of the Harvard scientists makes it plain that if the arrector pili muscles became more diminutive or were lost, it could very well compromise the overall function of the sympathetic nervous system in human skin, because the scaffolding for nerves of the sympathetic system would be lost.
The recognition that the arrector pili muscles prevent the sympathetic nerves from retracting away from hair follicles in mice suggests that this muscle functions in the same way in human skin. In mice and other mammals, the positioning of the sympathetic nerve is critical to stimulate the growth of new hair in response to ongoing exposure to cold. The same should be true in humans. Still, it is not clear at this juncture if hair growth in humans under these conditions would have any real benefit. On the other hand, there is no evidence to the contrary. We don’t know.
What we do know is that without the arrector pili muscles the sympathetic nerves would lose their positioning anchor in human skin. It seems perfectly reasonable to think that the proper positioning of the sympathetic nerve in the skin, in general, plays an overarching role in communicating changes in the environment to our bodies, helping us to maintain a homeostatic state.
In other words, because the muscle serves multiple purposes, it helps explain why these intact, fully functional muscles are found in human skin, with goosebumps produced as a by-product of the arrector pili’s association with hair follicles and sympathetic nerves. And who knows, maybe these muscles have added functions yet to be discovered.
There may be other reasons why we get goosebumps. They help us to pay close attention to the happenings in our environment. And, of course, this heightened awareness provides a survival advantage. On top of that use, goosebumps also provide social cues to others, signaling to them that we are cold or frightened, with the hope that these cues would encourage them to step in and help us—again, a survival advantage.
The cold truth is this: gaining a better understanding about the anatomy and physiology of the skin makes goosebumps less frightening for those of us who embrace a creation model approach to humanity’s origin.