One of the well known paradoxes of quantum mechanics is that light is both a particle and a wave. On its face this appears to be contradictory. In one state light appears to have its energy spread out, creating interference patterns if waves intersect. In another state, particles act, hitting things like sensors which allow us to operate remote controls for TVs and garage doors. There doesn’t seem to be a clear way to conceptualize light as being both at the same time. It’s not like the particles form a wave in the way water molecules form ocean waves. Rather, the essential nature of light is that it is both a wave and a particle at the same time. This is still unnerving to many, despite the physicist Nils Bohrs notion of complimentarity: these states are not contradictory but complementary, as you need both to describe reality.
I was thinking about this in light of recent discussions about whether or not social phenomena are simply the product of individuals making choices, or if humans are best seen as part of a larger whole, a society. There are some who view this distinction much the same way one is tempted to view the particle/wave issue. One can see the world is made up of discrete human identities making choices and, through their actions, producing some kind of social reality. As complex as that reality may be, it can be broken down to the individual actions, and explained at the individual level of analysis.
Others see the individual as being the product of social forces and cultural heritage. You are born into a particular circumstance, and depending on your position in society and your cultural and family environment, you develop in particular ways. The idea of being truly an individual is illusory; yes, we have identity, but who we are in this world reflects the forces acting upon us as much if not more than our own individual capacities.
Pondering these different views, I realized that it’s wrong to posit the question as if we had to choose between two positions – humans are individuals simply making choices and thus producing reality on the one hand, or society is a barrage of forces producing and empowering/constraining human identity on the other. That is to view these as contradictory. What if we saw them as complimentary?
In quantum physics, you see light as a wave or as a particle depending on what you are looking for. If you seek to measure its wave like properties, that is what you’ll find. The data won’t give you much information explaining how light functions as particles. It does tell you something though — you know that near the peak of the wave you’ve got a higher probability of finding a particle. As the wave spreads out, the probability goes down (this also opens the door to phenomena like quantum tunneling — atoms can appear on the other side of a barrier, as if one could suddenly walk through a wall. That is really strange, but if it didn’t happen we wouldn’t have our sun!) If you look to measure the particle functions of light, you’ll find a photon, but you won’t know much about the wave behavior.
Humans can be viewed the same way. If I want to examine the psychology of crowds or mass behavior, analyze statistical trends, and treat humans as something that can be studied as an aggregate collective entity, I can do that. Indeed, sociologists, political scientists, anthropologists and others have very convincing powerful theories that need no information about individual psychology or action. Highway engineers can study traffic patterns without having to figure out the psychology of the individual drivers. You can extrapolate downward (if crowd psychology works a certain way, than individuals must be reacting in particular ways) but you don’t need to.
If you want to study human psychology and behavior, you can do that too. You might be able to explain a lot about what a few individuals do, though it won’t be enough to explain the broad trends of history. It may give clues, but for most larger issues you have to go above the individual level of analysis to the cultural, governmental or even systemic.
Often these are seen as contradictory, and the battles between “methodological individualism” on the one hand, and “structuralism and social constructivism” on the other can be intense. In international relations theory this is known as the agent-structure problem. And like in quantum mechanics, there is a complementarity principle called constructivism. Humans are agents acting to reproduce or transform social structures, but individual actions are not enough unless they are part of a larger social or cultural movement.
So the issue of whether or not humans should be looked at as individuals only or as part of a social structure only is wrong headed. We are both, we cannot be understood as separate from our society and culture, but society and culture cannot exist without individuals. We are both particle and wave.
That last sentence is true on a couple of levels. Just as light is both particle and wave, so is matter. That means that all of us share that trait with light — we have wave lengths, and we have particles. We’re so big that the particle aspects (matter) of what we are become obvious, but every particle that makes up our bodies is both wave and particle. Paradox is the essence of reality.