Emotions are more contagious than any known virus. Although it influences everyone, emotional contagion affects some more than others. Aggressive people may be most affected. Disrespecting a "reactor" on the street can lead to child abuse later that day. Minor emotional put downs from strangers contribute to the paranoia of serial killers and plant more seeds of violence in the fertile minds of criminals.
Some people are consciously aware of subtle emotional transmissions around them. Some are able to perceive the invisible webs of emotion that connect us all. Their sensitivity is a blessing and a curse.
To understand the power of emotional contagion, consider its survival advantage in early human history. Sharing group emotions gives us multiple eyes, ears, and noses to sense danger and opportunity. Thus emotional contagion is common to all social animals - packs, herds, prides, and, in the case of early humans, tribes. When one member of the group becomes aggressive, frightened, or interested, the others do, too. Witnessing the fear or distress of another person in a group can easily invoke the same emotional state within us. Happy people at a party make us happy, caring people make us care, and the interested attract our interest. We avoid those who carry "chips on their shoulders" and those who "bring us down" or "make us anxious." Sporting events that lack at least a few excited spectators bore us. Theaters "paint the house" on opening night with audiences paid to be enthusiastic in the hope of influencing reviewers.
Like anything that affects emotional states, contagion greatly influences thinking. Opinion pollsters know that they get one set of responses to questions they ask of people in groups and another when they ask the same questions of individuals in private. It's not that these people are lying when in a group or that they change their minds when they're alone. It's more accurate to say that, at least on some issues, they have different public and private minds, due, in large part, to the influence of emotional contagion.
The principle of contagion accounts for "group think," which makes people act collectively against their better judgment. The high-risk behavior of teen gangs occurs as emotional contagion spurs each kid to move beyond personal inhibitions. Similarly, corporate and governmental scandals reveal how otherwise good people can get swept up in a frenzy that overrides their personal integrity. Emotional contagion produces solidarity parades, protest marches and, on the ugly side, "mob justice," lynching, riots, and looting. On a less dramatic level, it gives us constantly changing fashions, cultural fads, and political correctness.
Reactivity is resistance to the unconscious pull of emotional contagion. It can be obvious, as in, "I'm not putting up with your attitude!" Or it can be passive, e.g., trying to ignore you spouse's feelings.
The aspect of reactivity that makes it difficult to see, let alone change, is its illusion of free will and ego independence, even "authenticity." You think that you are acting of your own volition and in your best interest, when you are merely reacting to someone else. We've all uttered (or at least thought) the most ironic of all statements, "You're not going to bring me down!" As long as you're in this reactive mode, you are down - reacting to negativity with negativity, reacting to jerks like a jerk, reacting to abuse with abuse.
Science and Fiction
As a consultant for a new TV series, I helped develop a character who can sense subtle emotional transmissions among people, which evoke visions of future crimes, terrorist acts, and other disasters. She sets out to prevent the crimes and disasters she foresees, discovering along the way brighter and darker truths about herself, her family, and human nature.