00:00You are alone in a quiet room, nobody is behind you, nobody is even home, and yet the back
00:05of your neck crickles, your shoulders tense, and every instinct says someone is watching.
00:09You spin around and there is nothing there.
00:11So why did your body just sound and alarm, for I felt that does not exist, almost everyone
00:16has felt this.
00:17So is it a real sixth sense, or is your brain playing tricks on you?
00:21By the end of this video, you will know what scientists think is actually going on, and
00:25why this creepy feeling might be your brain doing exactly what it was built to do.
00:29And there is one built-in setting in your brain, found by researchers in Sydney, that explain
00:33why this feeling hits hardest in the dark, or when someone is wearing sunglasses, hold
00:38on to that, because it is the key to the whole mystery.
00:40Let's start over a hundred years ago.
00:42In 1898, a psychologist named Edward Pettinger published a short paper in the journal Science
00:47called The Feeling of Wearing Steered at.
00:49His idea was simple, we all feel a little nervous about our backs, because we can't see what
00:54is behind us.
00:55About 15 years later, another researcher tested it, volunteers sat with their backs turned,
01:00on some tries someone stared at them, on others nobody did, then the volunteers guessed which
01:04was big, their guesses were not better than chance.
01:07A few researchers have argued there is a small real effect, but most scientists remain unconvinced.
01:11So why does it feel so convincing?
01:13First you remember the hits and forget the mistakes.
01:15The one time you turn around and catch someone staring, it feels spooky, and you tell that story
01:20for years, but the hundred times you turn around and saw nothing, your brain quickly deletes them.
01:24It is called confirmation bias, and it makes a coincidence feel like a superpower.
01:28Second, your eyes are better detectives than dual eyes, even when you are not looking,
01:32your peripheral vision the edges of what you can see.
01:35Deep scanning, it can notice a head turning or a body angle towards you, and your brain raises
01:39a plaque before you consciously notice.
01:41Third, your brain can get spoiled by things you never consciously notice.
01:44A faint click for a footstep, too quiet to register can still set off the fear circles in the amygdala,
01:49the part of your brain that handles emotional reactions.
01:52Your brain hits an alarm with no explanation, so it drives when someone must be watching.
01:56Now remember that, built in sighting in our mansion, we are almost there.
02:00It is about what your brain does when it can't see someone's wife.
02:03In 2030, researchers at the University of Sydney found evidence that our brains start with a
02:07default assumption, when we can't tell where someone is looking.
02:10We lean toward assuming they are looking at us.
02:12And the results suggest that bias shows up especially when the cave is hard to see,
02:16like in the dark, or when someone is wearing sunglasses.
02:19One way to think about it has a better safe than sorry rule.
02:22If you wrongly think you are a pink wash, you get a shiver.
02:24If you wrongly think you are not, it could have caused our ancestor far more.
02:27So that prickle on your neck is not a psychic power.
02:30It is an ancient alarm, said to be a little oversensitive on purpose.
02:33When was the last time you felt washed, and where were you?
02:36Drop it in the comments, and I will tell you which of these explanations feels best.
02:57You told me it would get a 33 ago, and that's all the time.
