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Q: Mechanics of Shivers Up/Down the Spine ( Answered 5 out of 5 stars,   2 Comments )
Subject: Mechanics of Shivers Up/Down the Spine
Category: Miscellaneous
Asked by: hampsterhuey-ga
List Price: $6.00
Posted: 15 Jun 2005 18:53 PDT
Expires: 15 Jul 2005 18:53 PDT
Question ID: 533759
I would like to know what causes the sensation of shivers going up or
down one's spine. This is sometimes refered to as "the chills" or
"goosebumps," but I'm particularly interested in the tingling
sensation experienced (at least by me) in the middle of the back and
on the back of the neck.

I understand that the feeling is usually brought on by something
emotionally affecting, but am more interested in the biologic
processes that cause the sensation.

Is there a particular part of the brain that triggers the feeling, or
a common emotion? Is the sensation completely psychosomatic or is
there actually something going on in the areas I feel the tingling? Is
it related to the fight-or-flight response? What, if anything, is the
point of it; what is the evolutionary advantage of such a feeling, if
any? Is there a medical term for this?
Subject: Re: Mechanics of Shivers Up/Down the Spine
Answered By: crabcakes-ga on 15 Jun 2005 20:57 PDT
Rated:5 out of 5 stars
Hi hampsterhuey,

    Our hackles get raised when we are scared or very angry. This is
caused by tiny muscles at the base of tiny hairs that actually lift
the hair straight up.  It?s sort of a vestigial response left from
thousands of years ago, when humans had much more body hair, and a lot
more predators to worry about! It is due to the adrenaline rush we
get, called the pilomotor reflex, caused by the fight or flight
syndrome. Read on:
?You are watching a horror movie, you feel frightened and then get a
chill up your spine. In this case you were getting a negative
suggestion through your sensory perception (sight and sound), that
produced an emotion of fear which turned into the physical sensation
of chills up your spine. Visualization uses positive images to produce
positive emotions that manifest into positive physical sensations in
the body.?

?Our psychological/emotional state affects the endocrine system. For
example, the emotion of fear is related to adrenaline. If no feeling
of fear exists there is no adrenaline and the same applies in reverse-
no adrenaline, no fear. They work in relationship to each other.
Wherever a thought goes there is a body chemical reaction.

The hypothalamus, the emotional center of the brain, transforms
emotions into physical response. The receptor of neuropeptides, the
hypothalamus also controls the bodyís appetite, blood sugar levels,
body temperature, adrenal and pituitary glands, heart, lung, digestive
and circulatory systems. Neuropeptides, the chemical messenger
hormones, carry emotions back and forth between the mind and body.
They link perception in the brain to the body via organs, hormones and
cellular activity. Neuropeptides influence every major section of the
immune system, so the body and mind do work together as one unit.?

?Heat is sensed by the skin and the hypothalamus, as both contain
thermo receptors.  External environment temperature is sensed by the
skin, and internal environment temperature is sensed by the
            When it is cold outside, messages are sent from the
themoreceptors in the skin or from deep thermal receptors or via the
blood to the cerebrum and the hypothalamus.  The cerebrum makes the
person aware of being cold, and can cause behavioral changes which are
voluntary to, for example, put on a sweater.  When the message has
reached the hypothalamus, a series of reactions follow.  TRH (thyroid
releasing hormone) is released by the hypothalamus, its target organ
being the anterior lobe of the pituitary gland.  When TRH reaches the
pituitary gland, it releases TSH (thyroid stimulating hormone) into
the blood stream.  The target organ of TSH is the thyroid gland.  Upon
receiving TSH, the thyroid then produces thyroxin.  Thyroxin increases
cellular metabolism to make heat.
            Other things that happen:
            -vasoconstriction (blood diverted from skin to keep heat)
            -reduced sweating
            -skin hairs raised (erector pilli muscle contracted)
            -increased metabolic rate
            When it is too warm, messages are sent in the same way to
the hypothalamus.  This causes:
            -increased sweating to release heat via water
            -vasodilation (blood diverted to skin to lose heat)
            -skin hairs lowered,
            -reduced metabolic rate?

?Many animals, particularly including dogs and wolves, instinctively
raise their hackles when annoyed, threatened or scared. It's
presumably primarily done to make the animal look larger and more
menacing itself, plus may I suppose provide some slight greater degree
of protection to the neck area. Hence if something raises your hackles
or gets your hackles up, it makes you feel aggressively irritated or

?Both fear and anxiety send signals through the body that prepare all
systems for possible danger. Hormones, such as adrenaline and
catecholamine, are released in what is known as the "fight or flight"
response. The sudden increase in hormone levels speeds up the heart
and increases the amount of blood being pumped. At the same time, the
muscles tighten, increasing the individual's ability to fight or flee
from danger. The intensity of these physiological responses varies
according to the seriousness of the event or thought that sparked the
emotion, the strength of the individual's fear or anxiety, and his or
her previous experience and genetic makeup.

While both fear and anxiety can provoke an arousal response, their
other effects diverge. Very intense fear sometimes serves to "freeze"
the body to protect it from harm, causing little or no change in heart
rate and blocking the impulse to move. In anxiety, the physical
changes caused by arousal lead to a second stage marked by thought
patterns such as worry, dread, and mental replays of anxiety-arousing
As long as there's a good reason for fear or anxiety, and it doesn't
interfere with the ability to work, play, and socialize, it is not
considered a problem. But when anxiety takes on a life of its own and
begins to disrupt everyday activities, the situation is no longer
normal. A genuine emotional disorder is now at work . . . and it's
time to see a doctor.?

?Faced by a threat, your body responds with a complex cascade of
chemicals. The hypothalamus, alerted by the brain, pumps out a
specialized hormone that ultimately prompts the two adrenal glands
(perched atop the kidneys) to release the energizing hormone known as
adrenaline. The result?faster pulse, higher blood pressure, sharpened
awareness?is the "fight or flight" response to fear and anxiety.?

?The erector pili are smooth muscle fibers that give humans ?goose
bumps.? If the erector pili are activated, the hairs that come out of
the nearby follicles stand up and give an animal a larger appearance
that might scare off potential enemies and a coat that is thicker and
warmer. Humans, though, don?t have thick furs like their ancestors
did, and our strategy for several thousand years has been to take the
fur off other warm looking animals to stay warm. It?s ironic actually
that an animal, sensing danger is near, would puff up its coat to look
scarier, but the human hunter would see the puffier coat as a warm
prize, leaving the thinner haired weaker looking animals alone. Of
course, some body hair is helpful to humans; eye brows can keep sweat
out of the eyes and facial hair might influence a woman?s choice of
sexual partner. All the rest of that hair, though, is essentially

?And what about when you're ice skating or sledding and suddenly saying
"brrrr!!" When you are cold, your blood vessels keep you warm by
narrowing as much as possible, and keeping the warm blood away from
the skin's surface. You won't sweat at all, but you might notice tiny
bumps on your skin. Most kids call these "goosebumps," but the fancy
name for it is the pilomotor (say: pie-low-mo-ter) reflex. This is
when special tiny muscles called the erector pili (say: ee-reck-tur
pie-lee ) muscles pull on your hairs and make them stand up very
straight. This traps warm air between the hairs and keeps you warmer.?
?Our ancestors responded to stressful ordeals in this fashion.
Millions of years later, when you face a situation that you perceive
as challenging, your body automatically goes into overdrive, engaging
the stress response. Immediately, you release the same hormones that
enabled cave people to move and think faster, hit harder, see better,
hear more acutely, and jump higher than they could only seconds
earlier. Like theirs, your heartbeat speeds up; your blood pressure
increases; your breathing quickens. Most modern stresses, however, do
not call for either fight or flight. Our experience of stress is
generally related to how we respond to an event, not to the event

?·  Does fear help you focus? - I would argue not.  Remember, your
'fear system' governs several different specific responses in the face
of crisis- different parts of the brain regulate different fear
responses: one makes you cry (for outside help or mercy), one makes
you freeze when you're in danger (behavioral scientists believe this
helps many animals avoid detection by predators), one makes your
hackles go up and spurs aggressive behavior, (when spotted by a
predator, give the impression that you're fierce) etc... Depending on
your situation, fear can provide marginal benefits or prove utterly
disastrous.  Crying, freezing up, or flying into a rage will only
solve a certain few problems- but it will make most other situations
·  Does fear help you perform? - maybe.  Some people describe their
experience of cool performance under pressure as 'fear helping them to
perform'- they may be right, but I'm unconvinced.  My experiences with
paddling difficult water, where my focus is present, where time slows
down and my perception expands, doesn't feel like fear is really a
part of it.  I would actually argue that fear enters the picture
beforehand or afterwards, if it does at all.  ...and while it does
seem true that many use their fear as a prompt to make them focus, I
would argue that fear is the obstacle, rather than the agent, and that
moreover it's not necessary- one can focus without being afraid.?

I hope this has helped you out! If any part of my answer is unclear,
please request an Answer Clarification, before rating.

Regards, Crabcakes

Search Terms
Erector pili
Pilomotor reflex
chills + spine   -Christina Aguilera
hampsterhuey-ga rated this answer:5 out of 5 stars
Thanks a lot crabcakes, you covered all my questions thoroughly.
Though I suspected it was part of the fight-or-flight response, I was
surprised that the feeling is basically the same one my cat
experiences when I turn on the vacuum cleaner. Interesting stuff.

Subject: Re: Mechanics of Shivers Up/Down the Spine
From: crabcakes-ga on 16 Jun 2005 13:13 PDT
Glad to have helped! Thank you for the 5 star rating!
regards, Crabcakes
Subject: Re: Mechanics of Shivers Up/Down the Spine
From: freakxman-ga on 26 Apr 2006 02:48 PDT

I know I didn't pay for the answer, but is this the same reason you
get chills down your spine when experiencing something, well, good. 
Like watching someone get saved in a movie or seeing a patriotic

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