Unless you have alienated everyone around you, in the next two months you are likely to be invited to at least one party. If you take the perspective of a visitor from outer space, parties are actually sort of weird: "The humans gather in groups and consume food and other substances that make them dizzy. Using special equipment designed to produce loud sounds, they begin to hop around and become quite excited. Sometimes they even initiate their mating practices."
I was recently interviewed for an article about parties, and as I talked I realized how much recent research on imitation can help us understand about these odd behaviors. Survival among our non-human primate ancestors was tied to effective means of coordinating and sustaining social groups with increasingly flexible and complex means of adapting to their environments. One of the most effective means of coordinating groups is imitation, because it promotes group solidarity and allows for rapid learning.
We now know that there is a system of mirror neurons, probably present in all primates, but highly developed in humans. These specialized neurons fire both when we perform certain kinds of actions and when we observe others performing them. This means, for one thing, that we automatically imitate others much of the time, and the only reason we don't walk around imitating constantly is that we also learn, as we grow, to inhibit many of our neural impulses to imitate. Nevertheless, and this is the key point for parties, we still imitate others all the time, often without knowing we do so.
Thus, research has shown that if you are engaged in a lively conversation with someone, you will closely imitate their facial expressions. This will have two more or less inevitable consequences: so long as you sustain a lively conversation, you and your partner will tend to like one another. (In support of these points, see the articles and comments by Ap Dijksterhuis in Perspectives on Imitation) Second, you and your partner will begin to share emotions, because it is now widely accepted that emotions are triggered by associated facial expressions. As you know, a lively conversation can be very stimulating, even exciting: this is why.
Suppose you are in a setting where several small groups are having lively conversations. These folks are enjoying themselves and laughing. You are imitating those you are in conversation with, enjoying yourself, and feeling the happiness even of the other conversational groups. You are laughing and speaking excitedly-others hear this, and in turn they become more aroused and excited.
This emotional contagion may sound odd (aren't emotions supposed to well up from within our innermost selves?), but in fact it's an everyday sort of thing. An example I sometimes use to convey this to students: I ask them if they have ever been with a group of friends talking, and they have laughed so hard they felt they couldn't stop. Virtually everyone says they have had this experience. Now, I say, have you ever felt that way just sitting by yourself, not reading or watching a movie, when you just think of something funny? No one has ever claimed such an experience. The point is that we are usually capable of much more intense emotions in groups than as individuals.
Now of course, parties aren't just about conversations. There can be music, dancing, drinking, etc. But notice that all of these things also can lead to high arousal levels, even what might be called altered states of consciousness. Drums have been used since time immemorial to stimulate trance-we are highly susceptible to regularly repeated rhythms. Further, a lot of what happens with rhythm and dance is physical entrainment, a process that is closely related to imitation. Entrainment is another elemental motor process, deeply embedded in our evolutionary history, and it has been shown that infants who are but a few hours old will begin to synchronize bodily movements with their caretakers.
What does all this add up to? Intense collective celebrations have had important social functions for millions of years, even before our ancestors became human beings. At such events we find ourselves feeling emotions that we are not used to, we experience levels of arousal not familiar from day to day life, and we find ourselves doing things that we haven't really fully intended to do. This is why parties can be so much fun. They can be so stimulating that normal conventions of comportment may seem unnecessary or irrelevant, and at a really good party, people can get pretty crazy. Not you or me, of course, but those other humans...
To learn more, visit Peter G. Stromberg's website. Photo by Dennis Crowley.