For its six-part podcast, Invisibilia hosts Alix Spiegel and Lulu Miller examine the invisible stuff that shapes us.
Here are some of the remarkable morsels from the second episode, "Fearless."
1. Modern life triggers more fears than ever before.
We get scared for a reason: survival! But modern life relentlessly provokes our fear in ways natural living didn't, posits Caltech professor Ralph Adolphs, who has examined fear in human brains for decades.
We're simply not wired to see shootings and other reported horrors and ignore them, he says — and they trigger our anxiety when we don't need it.
2. Stranger danger used to be less of a thing.
Thirty years ago, environmental psychologist Roger Hart wanted to study children the way Jane Goodall studied baboons, so he mapped kids' adventures in a rural town, kind of like Harry Potter's Marauder's Map.
When he revisited the town see how far kids are allowed to venture now, the difference was astounding: Parents' invisible leashes are significantly shorter, and they're way more concerned with their kids' whereabouts at all times.
3. About 400 people on Earth can't feel fear.
It's called Urbach-Wiethe disease, and it's a rare genetic disorder that causes calcium buildup in the amygdala, the almond-shaped parts of your brain that sound the fear alarm.
While being fearless sounds like a superhero perk, it's actually incredibly dangerous. Even Spiegel and Miller, seasoned journalists, were unable to speak directly with SM, a woman who biologically can't feel fear. Her identity, age, and location are all kept secret so that no one takes advantage of her.
Because her physiology doesn't alert her of danger, SM has been held at knifepoint and gunpoint twice each, among other assaults. She has to rely on other tools in her brain belt, like logic, to get around. And as Spiegel points out, without fear, trauma is not traumatizing.
4. You can smell fear.
Well, sort of: It's not like you can spritz it on like Axe and make people scatter. But your brain does respond to disembodied fear particles, or Schreckstoff, which is German for "scary stuff." Scientists have shown skydivers' sweat alerts people to aggression faster than regular gross exercise sweat.
Alarm pheromones can alter other creatures' behavior, too. David Hu has broken down how snakes slither, but there's still an iota of mystery left about their weight distribution when they "walk." So it's very possible your fear of a snake can make it move a teensy bit faster. (You can check out more of his research here, if watching snakes slide around wearing a sock is your thing.)
5. Rejection therapy helps you be less afraid of hearing “no.”
Invented by an IT guy to curb his fear of rejection, the game has one rule: Have one person reject you every day. (You won't know if you don't ask, right?) You can take a 30-day challenge here.
The fear verdict: It's too much a part of us to take it out. But you can use this secret formula to help soothe it: fear = thinking + time. Take away either one and you take away fear.