Your Brain on Fear

Interesting article from Newsweek:

The evolutionary primacy of the brain’s fear circuitry makes it more powerful than the brain’s reasoning faculties. The amygdala sprouts a profusion of connections to higher brain regions—neurons that carry one-way traffic from amygdala to neocortex. Few connections run from the cortex to the amygdala, however. That allows the amygdala to override the products of the logical, thoughtful cortex, but not vice versa. So although it is sometimes possible to think yourself out of fear (“I know that dark shape in the alley is just a trash can”), it takes great effort and persistence. Instead, fear tends to overrule reason, as the amygdala hobbles our logic and reasoning circuits. That makes fear “far, far more powerful than reason,” says neurobiologist Michael Fanselow of the University of California, Los Angeles. “It evolved as a mechanism to protect us from life-threatening situations, and from an evolutionary standpoint there’s nothing more important than that.”

I’ve already written about this sort of thing.

Posted on January 9, 2008 at 6:10 AM27 Comments


John Moore January 9, 2008 6:58 AM

If the brain is plastic and can rewire itself, than the fear response can be rewired through training of the neocortex. If this were not so, then Buddhism and Christianity would not work and people have been known to overcome their greatest fear, the fear of death through these two philosophies which became religions.

Nick Lancaster January 9, 2008 7:22 AM

If the subject interests you, check out ‘A User’s Guide to the Brain,’ by John J. Ratey – he discusses the role of the amygdala among other things. (And, of course, the series ‘Firefly’ had one character whose amygdala had been tampered with as part of a government plot.)

Anonymous January 9, 2008 7:36 AM

Individual neurons are plastic but you can’t change the macro anatomy of your brain.

Ben H January 9, 2008 8:39 AM

Overcome the fear of death in the abstract, yes, but how many people could overcome their fear of a rabid bear?

John January 9, 2008 8:41 AM

My hand is connected to my arm, but that doesn’t mean it sends signals to it about what it’s doing. Through it, maybe. In the same way, I doubt brain architecture is so simplistic

sooth_sayer January 9, 2008 9:13 AM

You can’t reason when you are dead .. so the brain has been proven right by survival of this “genetic” trend.

Josh O January 9, 2008 9:16 AM

Well, this made perfect sense for when humans evolved in the wild. The only consequence to being overly fearful then was you hid out for awhile. The consequence for not being fearful enough was being eaten. So the perfect balance of fear and reason for living on the Savannah evolved, but it’s not working out in our modern world. If we quit being so compassionate and trying to save the stupid from themselves, we would eventually evolve to suit the present.

Mike Laird January 9, 2008 10:14 AM

Fear of death is one thing when contemplated from a church pew on a Sunday morning. It is another thing when you are 80 feet up on a cliff hanging on with your finger tips while rock climbing. The fear is there even if you have a rope on. Early in rock climbing, I found this fear nearly overwhelming and had trouble functioning. My wife never got past this stage and never got above about 15 feet off the ground. With practice, fear became a companion that told me things about my situation on a cliff face. Fear doesn’t go away, but some feedback loop can be learned to make it a useful companion. I suspect policemen, firemen, soldiers, etc. who regularly face intense, immediate fear develop a similar learned response. Maybe the brain science guys can figure this out some day.

Nick Lancaster January 9, 2008 10:31 AM


Oddly enough, if you risk your life to save ‘the stupid people,’ you are preserving genetic diversity.

Take the example of two brothers out exploring the woods. One brother loses his footing and falls into the river. Without aid, he will certainly drown.

If the remaining brother risks his life to save him, a successful attempt means both brothers are able to marry and produce offspring. If the remaining brother hesitates/declines, and his brother drowns, then only one of them is able to marry and produce offspring.

So while the odds of dying during the rescue attempt are high, it’s actually more sensible to take the risk.

Not to mention which, if we go by criteria like ‘the stupid people,’ it’s dumbing down society to the level of Survivor. We’re all on somebody’s list – too fat, too short, too tall, too good-looking, even too smart. Who gets to decide? You? Me? Bruce? Chuck Norris?

Anonymous January 9, 2008 10:56 AM

@Josh O:

“Well, this made perfect sense for when humans evolved in the wild. The only consequence to being overly fearful then was you hid out for awhile. The consequence for not being fearful enough was being eaten.”

I assert your model of behavior is incomplete, as you’ll die just as effectively if you can’t bring yourself to go to the water hole because you are too afraid. Continual fear is also an extremely stressful state to be in, and animals like that die faster.

“So the perfect balance of fear and reason for living on the Savannah evolved, but it’s not working out in our modern world.”

This is completely unsupportable bullshit. Even chickadees — brain size probably less than a gram — are capable of simple risk/benefit analysis, changing the parameters with their environment.

But amuse us: where are the dead bodies in support of your position?

Andrew January 9, 2008 11:53 AM

But amuse us: where are the dead bodies in support of your position?

Iraq. Sorry, couldn’t resist.

Given that we have to medicate a big chunk of our population just to get through daily life (prescription, legal, illegal, take your pick) . . . clearly something about the pressures of modern civilization and our brains is not working as well as one might hope.

Chuck January 9, 2008 11:59 AM


Today you amuse me, you get to live 🙂

This “preservation of genetic diversity” may be the reason that we all go down together – the inability to let some idiot get themselves killed keeps them alive and makes them a potential candidate for public office, where they’ll surely be put in charge and fail to follow our intelligent advice. Allowing people to do themselves in prior to reproductive age ensures a certain level of intelligence or luck in the surviving population. The current trend towards protection from danger or evaluation prevents such sorting from occurring until it is too late to be effective.

Nick Lancaster January 9, 2008 12:21 PM


In a perfectly fair and unbiased world, yes, the less successful members would eliminate themselves. Unfortunately, even the tendency to have padded corners on everything doesn’t seem to account for the increasing numbers of
‘teh st00pid’.

Taking your example of politics, we know that money (in itself, not a testimonial to genetic desirability) can mitigate the effects of stupid, including a cocaine and alcohol habit, so we wound up with said person in the White House.

Strict ‘survival of the fittest’ seems to be a reduced concern among larger populations, like humans. It’s not just the padded corners, but the ease of survival – we don’t hunt/gather, we go to the PigglyWiggly. We’re still effectively a herd animal, but the only true competition is among our own kind, and not an external predator, like cheetahs hunting gazelles.

Nick Lancaster January 9, 2008 1:51 PM

The amygdala and fear-fight-flight response (though within a species, ‘posture/submit’ is a fourth option) certainly were perhaps a better fit to our notion of our forebears as rock-wielding cavemen … but as to why, exactly, it hasn’t changed/evolved … perhaps the only difference between the cavemen and modern man is that the caveman had no pretensions of being civilized. We still fear the predator; that they tend to be other humans doesn’t change the mechanism. We still fear that which is different, else we’d have no need for anti-discrimination laws. We still operate on the fear-fight-flight-posture/submit model, no matter how much credit we give to our ability for higher reasoning.

If it could be shown that the amygdala was more developed in early man, then it might be possible to argue that it exists at a vestigial level, like pinky fingers and little toes … or that it shows how slowly evolution takes place in some cases.

Jared January 9, 2008 2:41 PM

how many people could overcome their fear of a rabid bear?

Well why would you want to? Fear of bears is a good thing to have. They are, after all, soulless killing machines.

brooklynwiseacre January 9, 2008 3:24 PM

Well why would you want to? Fear of >bears is a good thing to have. They are, >after all, soulless killing machines.

Oh yeah, but what about Yogi?

old guy January 9, 2008 3:48 PM

I wonder if Chuck Norris would get that ‘sharky feeling’ sitting past the break on his surf board.

HAL January 9, 2008 4:18 PM

Social networking is increasing security risk.

“Most users of social networking websites such as Facebook have no idea how their personal data can be used.” Lawyer UK
They don’t have any fear about feeding data into a website because they aren’t thinking about it.

dragonfrog January 9, 2008 7:31 PM

Yes, I understand this is in fun but – bears are actually not very aggressive (not counting polar bears). Treating them as reasonable works – you want to make sure they hear you coming, so they can get off a trail and give you room. If you see one, and think it might not be able to hear you (waterfall nearby or something) then you give them room, and make sure you’re visible from a distance.

Cougars on the other hand – don’t give them any credit for reasonableness.

bad Jim January 10, 2008 4:38 AM

Um, I once encountered a bear coming up a trail while I was going down. I stood off the trail (uphill traffic and pack animals have the right of way) and the bear chose to take a fork in the road.

Nick, about saving your brother: J.B.S. Haldane said he’d lay down his life for two brothers or eight cousins. In your scenario the brother on land might be better advised to get it on with his brother’s girlfriend (call it bereavement counselling) as well as his own.

To be or not to be January 10, 2008 12:11 PM

The brother who falls into the water is clumsy. Clumsiness could get future generations hurt and become burdens on society.

The brother who jumps in after the clumsy one is brave, but foolish. Foolish bravery gets his offspring killed taking foolish risks.

If the brother stays on the trail without either falling into the river (clumsy) nor drowning in a vain attempt to save his clumsy brother (foolish bravery), then his genes are prudent, and worthy of passing on.

bashful baboon January 11, 2008 11:17 AM

“I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.” – Paul Atreides

phred14 January 11, 2008 11:20 AM

The value of calm, competent people

Years ago, I was in a “fear situation,” a Boy Scout initiation at summer camp. The older scouts had all of the younger scouts whipped into a fearful frenzy over some imaginary threat, and of course they had whipped themselves into a fun-frenzy. At some point, I noticed the oldest scouts sitting at a table, books open, calmly doing their merit badge work. Though I was a tenderfoot, I got my book, sat with them, read, and calmed down, myself.

If found other times since then that the company of calm, competent people in times of fear can be a very good thing. At the very least, it can improve your own functioning.

Competent people may also be fearful.

Calm people may be missing the danger.

Calm and competent is the key.

Nix January 12, 2008 11:34 AM

Nick Lancaster and others, why would the amygdala’s fear response change? As Pinker and others have pointed out, it’s not that there is a fear response that’s a problem: it’s that it fires at the wrong things these days.

Fear of heights is certainly worthwhile, but the apparently innate fears of things like spiders, darkness, and large hostile wild animals aren’t much use these days outside Australia. Fears of driving under the influence and smoking would be much more useful, but a you can’t make changes like that in a few centuries.

Lamarck had organisms producing useful mutations on the fly as needed. Real evolution doesn’t work like that: the changes are random, and advantageous ones are selected for after that.

So Josh’s statement that ‘[i]f we quit being so compassionate and trying to save the stupid from themselves, we would eventually evolve to suit the present’ is only true if ‘the stupid’ are having less reproductive success than the non-stupid, and if our helping them is improving their reproductive success but not ours. In practice if you save someone’s life there are likely to be positive repercussions for you (the person who’s life you saved would be grateful, for starters).

If lots of people really did spend a lot of time and risk saving the life of entirely ungrateful non-relatives, then traits that led to not doing such things would eventually come to dominate, whereupon it would be in the interest of the non-relatives to become more grateful. (You don’t need awareness for this: similar events have been documented in interactions between the unrelated cells in slime molds.)

Evolution just happens. You don’t need to ‘help’ it.

Zeev January 18, 2008 10:49 PM

Reading last few issues of Crypto-Gram and some essays and blog entries, there seems to be the following argument forming, maybe not in a single article but connecting them together:

  1. Brain is more likely to act on Fear than on Reason
  2. Which makes Fear a good tool for politicians
  3. If Reason had its way we would be spending more on cancer research and less on anti-terror measures, since cancer kills more than terror
  4. Therefore it seems that politicians are deliberately doing wrong inefficient things for personal political gain.

This video (referenced in last Crypto-Gram) makes it particularly vivid:

Is this right, roughly? If so, I’d like to point out two flaws (even though I do agree with point (4) for million other reasons). Firstly, you just cannot use statistics when evaluating terrorism threat. The reason is that cancer is caused randomly, while terrorism is caused by intentional action of intelligent beings.

The crucial difference is that that the very goal of the terrorists is to change the statistics. And this invalidates statistical approach to terror, just as click fraud will invalidate Alexa rating for a website.

But secondly, and more importantly, the problem with blind statistics is trying to substitute it for reason. You cannot decide whether or not to go to war in some country based on number of terrorism victims last year. This is like deciding to invest in a stock based on the fact that it was on the rise 99 days out of last 100. You have to look at the fundamentals – what is the likely outcome of your action or inaction, and what is the cost of each option.

Terror statistics “works” when you evaluate a trip to a country where terror is present, or you think it is. This is when you say “in Israel X people died in exploding buses last year, Y died in road accidents”. If you’re reasonable, your conclusion would be to go by buses only. But in this kind of statistics you’re evaluating the whole system – government-terrorists-money-people-…, and you know what results it produced last year. Now, when you try to think as one component of the system (government) – that logic doesn’t apply. You cannot apply statistics that was derived from your actions last year to your actions this year. This is because your actions last year were based on real facts and threats last year (one hopes), and this year brings a new picture.

As a government, saying “I was successful last year spending $X, so I should spend the same this year” doesn’t work. You were not successful spending $X, you were successful analyzing the real picture, and the outcome was spending $X. If you want to repeat your success, you need to keep analyzing the real picture, and not blindly repeat the same moves.

So all I’m saying is that as individuals, we should keep acting out of Reason and refuse to be terrorized, just because we know historically, how dangerous various things are in our environment. (That environment includes rational terrorists who want to kill us and rational government who wants to stop them). However, we cannot take this argument to the government and say (just based on statistics) “you’re spending way too much”. Statistics doesn’t say how much to spend. This is why you still need brains to run a country.

Leave a comment


Allowed HTML <a href="URL"> • <em> <cite> <i> • <strong> <b> • <sub> <sup> • <ul> <ol> <li> • <blockquote> <pre> Markdown Extra syntax via

Sidebar photo of Bruce Schneier by Joe MacInnis.