Goosebumps: Primal Reflex, Emotions, & Hair Growth
This podcast details goosebumps, or piloerections, as an involuntary reaction of the sympathetic nervous system, part of the fight-or-flight response, where tiny arrector pili muscles at hair follicles contract, making hairs stand on end.
Common triggers include cold weather, intense emotions such as fear, shock, anger, or excitement, as well as intimacy, sexual arousal, and frisson from external stimuli like music, movies, or ASMR.
Evolutionarily, goosebumps helped furry animals conserve heat by trapping an insulating layer of air and made them appear larger to deter predators. A recent study revealed a deeper purpose: the nerves and muscles causing goosebumps also stimulate hair follicle stem cells and new hair growth, acting as a long-term response to cold. This involves sympathetic nerves directly interacting with stem cells and releasing neurotransmitters like norepinephrine.
Psychologically, experiences like music can trigger goosebumps when the emotional brain perceives an unexpected stimulus as a threat, followed by the thinking brain's cognitive reappraisal, which releases dopamine and creates a pleasurable sensation known as frisson or a "skin orgasm".
While generally harmless, persistent goosebumps without a clear cause can sometimes be a symptom of underlying conditions such as keratosis pilaris, anxiety, withdrawal from substances, certain types of seizures (e.g., left temporal lobe epilepsy), or autonomic dysreflexia.
0.000000 6.000000 Welcome to every day explained your daily 20-minute dive into the fascinating house and wise of the world around you.
6.000000 11.000000 I'm your host Chris and I'm excited to help you discover something new. Let's get started.
11.000000 13.000000 Okay, let's jump right in.
13.000000 19.000000 Today we're tackling something everyone gets, but maybe doesn't think much about goose bumps.
19.000000 23.000000 Right, that weird sudden kind of prickly thing your skin does.
23.000000 25.000000 Exactly. It's in some minor, doesn't it?
25.000000 30.000000 No, it's not just about being cold, is it?
30.000000 36.000000 No, not at all. That's what makes it interesting. You get them from music, movies, strong emotions.
36.000000 42.000000 Yeah, so we've looked at some research papers, some health explainers trying to really get out of the skin of it.
42.000000 43.000000 Someone intended.
43.000000 51.000000 Huh, maybe. But yeah, the mission today is to unpack the science, the history, maybe some surprising new stuff.
51.000000 54.000000 Really figure out what's raising your hair and why it even matters.
54.000000 59.000000 And maybe have a chuckle about our slightly odd primal brain wiring along the way.
59.000000 64.000000 Definitely. Okay, let's get started. So first things first, what are goose bumps, technically?
64.000000 67.000000 Well, the proper term is pyloeirection, pyloeirection.
67.000000 68.000000 Pyloeirection, okay.
68.000000 72.000000 And it's fundamentally an involuntary reflex. Your body just done it.
72.000000 75.000000 It's controlled by the sympathetic nervous system.
75.000000 78.000000 Sympathetic nervous system. That's the fight or flight one, right?
78.000000 83.000000 Exactly that. It handles all the automatic stuff, breathing, heart rate, digestion.
83.000000 87.000000 And yeah, that immediate response to perceived threats or intense stimuli.
87.000000 90.000000 So how does that system make the bumps happen?
90.000000 94.000000 Okay, so at the base of every single hair follicle, you have these tiny, tiny muscles.
94.000000 96.000000 They're called erector peely muscles.
96.000000 99.000000 Erector peelys, like hair erectors.
99.000000 107.000000 Pretty much. And when the sympathetic nervous system sends the signal, maybe because you're cold or scared or hearing amazing music, these little muscles contract.
107.000000 108.000000 And they tense up.
108.000000 109.000000 Yeah, they tighten.
109.000000 114.000000 And because they're attached to the hair follicle, that contraction pulls the hair so it stands straight up.
114.000000 117.000000 Ah, and that pull bunches up the skin around the hair.
117.000000 120.000000 Precisely. That little bunching is the bump you see and feel.
120.000000 123.000000 Wow. So tiny muscles attached to every hair.
123.000000 125.000000 That's kind of wild. Does that happen everywhere?
125.000000 128.000000 Pretty much anywhere. You have hair follicles and these muscles.
128.000000 131.000000 Arms, legs, neck, even your scalp sometimes.
131.000000 134.000000 Not places like your palms or the soles of your feet, obviously.
134.000000 139.000000 Okay, so that's the how tiny muscles pulling hairs up. But why?
139.000000 143.000000 Why did we evolve this? Feels a bit useless for us humans.
143.000000 148.000000 That's the million dollar question, isn't it? It's definitely an evolutionary hand me down.
148.000000 150.000000 From when we were furrier.
150.000000 156.000000 Exactly. Think about animals with thick coats, dogs, cats, bears.
156.000000 161.000000 For them, pylowirection serves two really clear purposes.
161.000000 162.000000 Okay, what are they?
162.000000 169.000000 First is insulation. When all that first stands on end, it traps a thicker layer of air right next to the skin.
169.000000 171.000000 Like putting on a puffer jacket.
171.000000 176.000000 Kind of, yeah. That tracked air acts as an insulator helping them stay warmer in the cold.
176.000000 178.000000 Makes sense. And the second reason.
178.000000 181.000000 Making themselves look bigger, scarier.
181.000000 183.000000 Ah, the Halloween cat effect.
183.000000 191.000000 Precisely. When an animal feels threatened, puffing up its fur makes it appear larger and more intimidating to a potential predator or a rival.
191.000000 192.000000 It's a visual warning signal.
192.000000 195.000000 Okay, both make total sense for a furry animal.
195.000000 199.000000 But for us, I mean, my arm hairs standing up aren't going to keep me warm, really.
199.000000 201.000000 Not significantly, no.
201.000000 203.000000 And I'm definitely not scaring anyone off by looking slightly bumpier.
203.000000 206.000000 Chuckles, probably not. And that's the puzzle, isn't it?
206.000000 211.000000 We've lost most of our body fur, so those original functions are, well, pretty much obsolete for us.
211.000000 214.000000 So why keep the reaction? It seems like a leftover bit of code.
214.000000 216.000000 That's what's fascinating.
216.000000 220.000000 It suggests there might be other reasons, or maybe the system got co-opted for other things.
220.000000 223.000000 Which leads us right into all those other triggers.
223.000000 225.000000 Right, the emotional stuff. The source is mentioned quite a few.
225.000000 230.000000 Yeah, beyond cold, you get goose bumps from really intense emotions.
230.000000 237.000000 Fear, obviously, but also shock, anger, awe, even great excitement or joy.
237.000000 239.000000 And physical things too, right, touch.
239.000000 245.000000 Definitely. Certain kinds of touch, intimacy, sexual arousal, even being tickled to trigger it.
245.000000 250.000000 I get them sometimes just from like a really sudden noise or a jump scare in a film.
250.000000 251.000000 Even if I know it's coming.
251.000000 252.000000 Totally normal.
252.000000 253.000000 Yeah.
253.000000 258.000000 And that specific kind of trigger the one from external things like music or movies, researchers have a name for it for song.
258.000000 259.000000 For a song?
259.000000 261.000000 Sounds fancy, like a French shiver.
261.000000 265.000000 It basically means aesthetic chills or psychogenic shivers.
265.000000 272.000000 It's that tingling, sometimes shivery sensation you get from stimuli that aren't about immediate physical danger or temperature.
272.000000 277.000000 So listening to an amazing piece of music or watching a really powerful scene, that's free song.
277.000000 278.000000 Exactly.
278.000000 281.000000 That wave of tingles up your spine or arms.
281.000000 286.000000 It can happen with powerful speeches, certain visual art, even ASMR for some people.
286.000000 289.000000 Someone in the research actually called it a skin orgasm, didn't they?
289.000000 290.000000 Laughs. They did.
290.000000 293.000000 It's certainly a memorable way to put it.
293.000000 298.000000 But it does capture that intense, pleasurable, yet involuntary physical reaction.
298.000000 299.000000 Some people experience.
299.000000 303.000000 Okay, my skin having orgasms is a thought.
303.000000 305.000000 But seriously, how does that work?
305.000000 311.000000 How does a beautiful song connect to the same system that's meant to react to, like a predator jumping out?
311.000000 312.000000 Feels like cross wires.
312.000000 317.000000 It does seem like a mismatch, but the thinking is about how our brain processes unexpected things.
317.000000 321.000000 The sources talk about this idea of like two brain systems working in parallel.
321.000000 324.000000 The old emotional brain and the newer thinking brain.
324.000000 329.000000 You got it, the emotional brain think a migdala limbic system is ancient.
329.000000 332.000000 It's super fast and it's main job is survival.
332.000000 336.000000 It's constantly scanning for anything unusual, anything potentially dangerous.
336.000000 337.000000 Look at radar system.
337.000000 338.000000 Exactly.
338.000000 341.000000 Like that bunny in the forest, always listening for the snap of a twig.
341.000000 345.000000 It reacts instantly to sudden changes or unexpected patterns.
345.000000 348.000000 So allowed noise, a sudden shift in harmony in music.
348.000000 352.000000 To that primal brain which doesn't understand art or movies,
352.000000 357.000000 those are just signals that something is different, something unexpected is happening.
357.000000 361.000000 And its default reaction is potential threat, alert.
361.000000 362.000000 Wow.
362.000000 368.000000 So a powerful chord change could literally trigger a danger signal in that old part of my brain.
368.000000 373.000000 In a way, yes, it's the unexpectedness, the deviation that trips the alarm.
373.000000 376.000000 And that alarm signal goes straight to the sympathetic nervous system.
376.000000 378.000000 Which tells the erector pilli muscles.
378.000000 382.000000 Contract, prepare for action, and boom, goosebumps.
382.000000 386.000000 It's the body's instant physical reaction to that potential threat signal.
386.000000 388.000000 Okay, but almost immediately, I know it's just music.
388.000000 390.000000 I'm not actually in danger.
390.000000 391.000000 Right.
391.000000 395.000000 That's where your thinking brain, the pre-funkel cortex and other higher level areas comes in.
395.000000 397.000000 It catches up very quickly.
397.000000 399.000000 It assesses the situation properly.
399.000000 402.000000 Yes, it performs what researchers call a cognitive reappraisal.
402.000000 405.000000 It looks at the context and says, hold on, that wasn't a screen.
405.000000 406.000000 That was just a high note.
406.000000 409.000000 It wasn't a safe, it's music, or that wasn't an attack, that was just a tickle.
409.000000 411.000000 False alarm, everyone stand down.
411.000000 412.000000 Exactly.
412.000000 417.000000 The thinking brain overrides the initial panic signal from the emotional brain.
417.000000 420.000000 The fight or flight response starts to calm down.
420.000000 422.000000 But then something else happens, right?
422.000000 423.000000 Something rewarding.
423.000000 425.000000 This is the really cool part.
425.000000 429.000000 When the thinking brain successfully identifies the threat as benign,
429.000000 432.000000 when it resolves that initial tension or surprise,
432.000000 435.000000 your brain releases dopamine.
435.000000 437.000000 The feel-good chemical.
437.000000 438.000000 Yep.
438.000000 439.000000 It's like a little reward.
439.000000 442.000000 Wait, so evolution is rewarding me with happy juice
442.000000 446.000000 for figuring out that the sudden loud bit in the movie wasn't a real monster.
446.000000 448.000000 That seems to be the theory.
448.000000 450.000000 It's like your brain says nice job.
450.000000 452.000000 You correctly assess the situation.
452.000000 453.000000 Realized it wasn't dangerous.
453.000000 455.000000 Here's a little dopamine hit for your trouble.
455.000000 458.000000 So my body gives me goosebumps at a primal fear
458.000000 460.000000 from Celine Dion hitting a high note.
460.000000 464.000000 And it gives me a dopamine reward for realizing it's just Celine Dion and not,
464.000000 466.000000 I don't know, a "terradactyl screaming."
466.000000 467.000000 Bluffing.
467.000000 472.000000 That's a pretty accurate, if slightly absurd summary.
472.000000 476.000000 It connects to why we enjoy things with tension and release,
476.000000 480.000000 scary movies, thrilling music, even tickling to some extent.
480.000000 483.000000 There's that initial jolt, the primal alert.
483.000000 484.000000 Who's Bubs?
484.000000 485.000000 Followed by the cognitive reappraisal.
485.000000 486.000000 Oh, it's okay.
486.000000 490.000000 And then the pleasurable dopamine release associated with resulting that tension.
490.000000 494.000000 The joy of figuring it out or surviving the false alarm.
494.000000 497.000000 That is genuinely hilarious and makes so much sense.
497.000000 498.000000 Right.
498.000000 499.000000 Our brains are weird.
499.000000 500.000000 Wonderful, weird.
500.000000 501.000000 Okay, let's switch gears a bit.
501.000000 503.000000 Because there's this other reason goosebumps are important, right?
503.000000 504.000000 Yes.
504.000000 505.000000 Something newly discovered.
505.000000 509.000000 Linking back to the physical side, the cold response.
509.000000 513.000000 Yes, this is really fascinating work coming out of places like Harvard and NIH.
513.000000 517.000000 They've found a deeper, more functional reason why this whole system might have stuck around.
517.000000 520.000000 Even in relatively hairless humans.
520.000000 521.000000 Don't keep me in suspense.
521.000000 522.000000 What is it?
522.000000 526.000000 They figured out that the sympathetic nerve, the same one that triggers the erector pilly muscle
526.000000 528.000000 to contract and cause the goosebumps.
528.000000 529.000000 Yeah.
529.000000 530.000000 It doesn't just talk to the muscle.
530.000000 535.000000 It also directly connects to and communicates with the hair follicle stem cell.
535.000000 536.000000 The stem cells.
536.000000 538.000000 The ones that actually make the hair grow.
538.000000 539.000000 The very same ones.
539.000000 540.000000 And here's the kicker.
540.000000 544.000000 The little erector pilly muscle itself plays a crucial role.
544.000000 547.000000 It's not just the motor, it acts like a physical bridge.
547.000000 548.000000 A bridge.
548.000000 551.000000 Yeah, it provides the necessary structure like an anchor point
551.000000 555.000000 that allows the nerve fibers to physically reach and connect properly
555.000000 558.000000 with those stem cells in the follicle niche.
558.000000 563.000000 So the muscle has to be there for the nerve to talk to the stem cells correctly.
563.000000 564.000000 That's what the research suggests.
564.000000 566.000000 It's essential for that connection.
566.000000 570.000000 And what they found is that under prolonged cold, not just a quick shiver,
570.000000 572.000000 but sustained cold exposure.
572.000000 574.000000 Like being outside for a while in winter.
574.000000 575.000000 Right.
575.000000 577.000000 The sympathetic nerve activity ramps up.
577.000000 578.000000 It gets more active.
578.000000 581.000000 And it releases more of a neurotransmitter called norm up and vine.
581.000000 582.000000 Norkin effron.
582.000000 584.000000 That's a stress hormone, isn't it?
584.000000 585.000000 It is.
585.000000 588.000000 And when this norkin effron is released near the hair follicle stem cells,
588.000000 591.000000 thanks to that nerve connection supported by the muscle,
591.000000 593.000000 it does something crucial.
593.000000 595.000000 It activates the stem cells.
595.000000 596.000000 It wakes them up.
596.000000 597.000000 Essentially, yes.
597.000000 601.000000 It signals them to start proliferating to regenerate the hair follicle.
601.000000 604.000000 And over the longer term to grow new hair.
604.000000 605.000000 Whoa.
605.000000 606.000000 Okay.
606.000000 607.000000 Hold on.
607.000000 611.000000 So the same system that causes the immediate short term goose bump reaction to cold.
611.000000 612.000000 Yes.
612.000000 617.000000 Is also using that same nerve signal, especially when the cold lasts.
617.000000 620.000000 To tell the stem cells, hey, it's seriously cold out here.
620.000000 622.000000 We need a thicker coat to start growing more hair.
622.000000 623.000000 You've nailed it.
623.000000 625.000000 That's the dual function they uncovered.
625.000000 627.000000 Goose bumps are the rapid short term response.
627.000000 632.000000 But the underlying nerve activity also triggers the long term adaptation,
632.000000 635.000000 stimulating hair growth for better insulation down the line.
635.000000 636.000000 That's brilliant.
636.000000 637.000000 It's a two-pronged strategy.
637.000000 640.000000 Immediate reaction plus a plan for the future.
640.000000 641.000000 Exactly.
641.000000 647.000000 It turns what look like a vestigial reflex into part of a really sophisticated integrated system
647.000000 651.000000 for regulating body temperature and adapting to the environment over time.
651.000000 655.000000 And the muscle is key, not just for the bump, but for enabling that long term signal.
655.000000 656.000000 Right.
656.000000 659.000000 They even found the whole system develops in a coordinated way.
659.000000 664.000000 The follicle tells the muscle where to form and the muscle then attracts the nerve to connect everything up.
664.000000 666.000000 It's beautifully orchestrated.
666.000000 667.000000 I'm blown.
667.000000 668.000000 Okay.
668.000000 671.000000 So wrapping this all together, why does understanding all this matter?
671.000000 675.000000 Beyond just satisfying curiosity about weird skin bumps.
675.000000 680.000000 Well, on a basic science level, it's a great example of how different cell types,
680.000000 686.000000 nerves, muscles, stem cells, coordinate and communicate, and how environmental signals like temperature
686.000000 690.000000 can directly influence fundamental processes like stem cell behavior.
690.000000 694.000000 And that specific finding about the muscle bridge and nerve stem cell communication,
694.000000 697.000000 that sounds like it could have practical uses.
697.000000 698.000000 Potentially, yes.
698.000000 702.000000 Understanding this pathway could be really important for regenerative medicine,
702.000000 704.000000 especially as you might guess, for hair loss.
704.000000 705.000000 Also.
705.000000 710.000000 The sources mentioned that in common baldness, like male pattern baldness, those tiny erector
710.000000 713.000000 pilly muscles are often lost along with the hair follicle shrinking.
713.000000 718.000000 Ah, so if the muscle bridge is gone, the nerve can't properly stimulate the stem cells anymore.
718.000000 721.000000 That could be a contributing factor exactly.
721.000000 726.000000 So if researchers can figure out how to reactivate those stem cells, maybe by mimicking the
726.000000 732.000000 nerve signal or finding ways to restore that connection, it could lead to new treatments.
732.000000 735.000000 So, maybe even other skin issues, wound healing.
735.000000 736.000000 Possibly.
736.000000 740.000000 Anywhere that nerve stem cell communication in the skin is important.
740.000000 743.000000 Understanding this mechanism could provide new therapeutic targets.
743.000000 745.000000 It's early days, but promising.
745.000000 746.000000 Amazing.
746.000000 752.000000 So the solution to hair loss might be hidden in the mechanism behind getting chills during a scary movie.
752.000000 755.000000 It's certainly connected in unexpected ways.
755.000000 757.000000 Now, just a quick medical side note we should touch on.
757.000000 760.000000 While goosebumps are almost always totally harmless.
760.000000 761.000000 Yeah.
761.000000 762.000000 Very, very rarely.
762.000000 767.000000 If someone experiences them constantly, without any obvious trigger, like cold or emotion,
767.000000 769.000000 it could be linked to an underlying condition.
769.000000 774.000000 Things like certain skin disorders, maybe anxiety, withdrawal from some substances,
774.000000 778.000000 or in super rare cases, neurological issues, or something called autonomic dysreflexia.
778.000000 782.000000 But that's persistent, unexplained goosebumps, and it's really uncommon.
782.000000 783.000000 Exactly.
783.000000 785.000000 Extremely uncommon.
785.000000 790.000000 For 99.9% of us, goosebumps are just a normal, everyday physiological response.
790.000000 791.000000 Nothing to worry about.
791.000000 796.000000 Just our body doing its complex, slightly weird, but ultimately fascinating thing.
796.000000 797.000000 Precisely.
797.000000 798.000000 Wow.
798.000000 799.000000 What a deep dive.
799.000000 804.680000 We went from ancient fur coats and looking scary to emotional roller coasters and dopamine hits
804.680000 810.000000 from music all the way to cutting-edge stem cell science and potential hair loss treatments,
810.000000 812.000000 all packed into that little bump on your skin.
812.000000 815.000000 It really shows how interconnected everything is, doesn't it?
815.000000 821.000000 The nerves, muscles, stem cells, emotions are evolutionary past, all playing a role in this
821.000000 823.000000 one simple, seeming reaction.
823.000000 826.000000 And sometimes our primal brain gets hilariously confused by art.
826.000000 827.000000 Chuckles.
827.000000 828.000000 That too.
828.000000 831.000000 It's a great reminder of the layers of complexity hidden within us.
831.000000 832.000000 Absolutely.
832.000000 834.000000 Okay, so here's something for you, our listeners, to think about.
834.000000 839.000000 The next time you feel those bumps rise on your skin, whether you're cold, scared, moved
839.000000 842.000000 by a song, whatever it is, just take a second.
842.000000 846.000000 If you're experiencing this ancient reflex, it's not just about the now, but might also
846.000000 850.000000 be signaling your body to prepare for the future, and maybe your brain is giving you a tiny
850.000000 852.000000 reward for not panicking.
852.000000 853.800000 It makes you wonder, doesn't it?
853.800000 858.400000 What other everyday things our bodies do have these incredible hidden stories and complex
858.400000 861.200000 mechanisms just waiting to be uncovered?
861.200000 864.160000 And that wraps up today's episode of Everyday Explained.
864.160000 867.640000 We love making sense of the world around you five days a week.
867.640000 872.480000 If you enjoyed today's deep dive, consider subscribing so you don't miss out on our next discovery.
872.480000 874.720000 I'm Chris, and I'll catch you in the next one.