You may have already seen the video of a fellow named Phil Davison who is running for treasurer in Stark County Ohio. Mr. Davison says he has a master's degree in communication. Must have been communications theory, not practice, because Mr. Davison seems like a classic example of just how nervous people can be when they have to speak in public. (Either that, or he's taken some VERY powerful stimulants.)
Common fears (not phobia...excessive fear) fall into two categories; physical threats, and social threats. The first group includes the good old standard scary things, the stuff they used all the time on "Fear Factor" - snakes and spiders and rodents and heights and enclosed spaces - physical hazards. Sure enough, when you put test subjects in a functional magnetic resonance imaging (fMRI) machine that can detect blood flow down at the cellular level and illuminate which parts of the brain are active, and you flash pictures of these objects to the subjects, one of the neural areas that becomes most active is the amygdala, the little chunk of specialized cells just above the brain stem where fear starts. The amygdala knows to sound the alert and trigger a fear response when it detects potential danger. Interestingly, the same "Be afraid" cells in the amygdala also sound the alarm when we hear scary music, or see scary faces. The amygdala, about which I've written before and which gets it's own chapter in "How Risky Is It, Really? Why Our Fears Don't Always Match the Facts" , is a fantastic little section of the brain, your 24/7 radar for possible danger.
It turns out the amygdala also goes off when people are confronted with the other risks on the Top Ten Things You're Afraid of lists; social risks, like public speaking, and fear of rejection, and fear of failure. Standing up in front of an audience to speak sets off the same hard-wired "protect me" biological systems as a snake or a scary face! Why?
Here's my two cents worth, NOT based on any hard science but on the general principles of evolutionary psychology and a pretty good familiarity with the risk response system in general, both the neuroscience and the psychology. It's scary to be rejected because, as social animals, we depend on our tribe for our own wellbeing, even our survival. If the lion is attacking, alone we're lion food. Together we have a chance. Time to go hunt down a wooly mammoth for dinner? Better bring the guys because your chances of killing prey are much less if you hunt alone. We depend on our tribes. As our tribe's chances go, so go ours.
That means that rejection by the tribe doesn't just make you sad, it makes you scared. It's dangerous. If the lion is attacking and the rest of the tribe rejects you (maybe because you were a lousy story teller at the group's campfire the night before) you're in real trouble. So any hint of social rejection - from an audience, a boss, a friend, a lover - would set off the same alarms that a snake does. There actually is some hard science on this, which suggests that social cues are highly relevant down in the amygdala.
A lot of research has found that the human hormone oxytocin is associated with feelings of trust, and that levels of oxytocin increase with signs that you are liked/love/accepted, like gentle touching and other cues. Sure enough, if you expose test subjects to a sniff of oxytocin, and watch their brains in an fMRI while you ask them to make choices about whether to trust someone with their money, the amygdalas of the subjects who snorted the hormone do NOT light up as much as those who do not get a sniff of Eau-de-Trust. In other words, our amygdalas, our early warning radar, are set to be slightly skeptical and socially wary, but when we experience cues of being liked/love/accepted our oxytocin levels go up and that turns out inherent skepticism and mistrust down. More oxytocin = less wariness. And this all sensitivity to social cues happens down in the amygdala, the neural hardware at the heart of our risk perception system.
So pity poor Mr. Davison, an overnight internet icon for his wild campaign speech. It's a pretty safe bet that his amygdala was going berserk during his obviously nervous performance. But hey, don't blame him. He was only trying to survive! Check out the video yourself. If you're nervous about public speaking, you might recognize a little bit of yourself in what you see.