Goleman opens Social Intelligence with a personal anecdote about an unpleasant encounter with a security guard, in which the man’s needless aggression left Goleman with a lingering feeling of upset he could not shake for some time. Goleman introduces the concept of “emotional contagion,” a phenomenon in which other people’s emotions transfer to the people witnessing them. This phenomenon operates mainly through the activation of the amygdala, which automatically intensifies our focus and starts scanning for threats at any sign of upset or emotional turmoil from another person. The amygdala is most widely known as the source of “fight or flight” impulses in response to danger, but the amygdala is also very sensitive to perceived emotional threats as well as perceived physical ones. This amygdala response primes a person to experience a bit of whatever emotion they are perceiving in others, be it fear, shock, anger, or joy. Goleman then introduces the intuitive, unthinking system of warning and observation fueled by the amygdala, which he calls the “low road.” Goleman relates a second anecdote about a man who lost the use of his visual cortex, becoming functionally blind. However, he was still able to gauge expressions accurately on people’s faces, even though he could not see them.