Things change. People change. Societies change. You might not be able to get social scientists and cultural theorists to agree on very much, but the fact that change happens is pretty easy to stomach. The difficulty come in when we start to think about how things change. What follows is a review of the competing approaches to what I'm calling "theories of change," I hope this helps me (and you!) organize some thoughts.

There are, near as I can tell, three major schools of thought that attempt to explain "how things change:" evolution, complexity/emergence (chaos), and development. In turn:


Derived of course from biology, there's a great deal of evidence that biological systems have evolved and continue to evolve. Evolution is predicated on the assumption that the most adaptive variations in a given population will propagate themselves more than less adaptive variations, which will propagate themselves less. Evolution is a very "big picture" process, and--at least in the biological sense--refers to change and adaption on the scale of the population on the whole.

There are a few things that more casual applications of the theory seem to forget that I think are key:

  • Evolution values adaptability and diversity over just about everything else, adaptable individuals and diverse populations are more resilient to shorter term changes in the environment, so evolutionary analysis that's grounded in survivability in a particular situation are relatively week.
  • Evolution takes a long time. Many generations. Many many generations. So many that it's really hard to think about evolution "happening" given the way that we think about time. In many ways, its easier to think about continents moving around than it is to think about the way populations evolve.
  • There's little good evidence that evolution occurs in non-biological systems. We use evolution as an analogy for many change-processes, but as a mechanism, outside of biology its limited.


I really like complexity or emergence theory, but I'm not a math guy, and I don't have a very good grasp of it. The basic idea is that in the right conditions, systems of independent "actors" that interact with each other will given time develop some sort of organization, and that these "systems" (as actors) combine to form higher level systems. And so forth.

So for example, humanity can be seen as an example of emergent complexity: our bodies are made up of molecules that interact with each other to form sub-cellular structures and cells (actors), which make up tissues and then organs (systems), which make up our bodies. Our bodies (and selves) are actors in social systems... and so forth. I've left a lot out. Obviously evolution is an example of a complexity theory, but complexity theories have been used (successfully, I'd argue) to explain how systems work and form in non-population scale biological systems and non-biological systems, and also on time scales that are shorter than anything evolution could work with.

The organization of photographs in tags on flickr is largely emergent (as are google's search results), and intelligence is often described as being emergent. There are more, and I'm sorry if I don't have really good examples of this.


I use the idea of development to help describe smaller scale adaptations and adjustments over time. I studied a lot of Developmental Psychology for a while in there, and I think a concept of development is really important to thinking about the ways people change, and grow. Just as we know that evolution happens to populations over time, we know that humans (and other animals) are continuously developing throughout their existences.

Human development has two major divisions: the intrinsic biological processes and the process of adapting to different contexts. The biological stuff is pretty limited: it's impossible to walk or develop speech before a certain age because the vocal/skeletal musculature isn't developed enough. Stuff on that scale. These sorts of biological/physical limitations are developmentally relevant mostly because they limit the possibility for external experience.

The adaptation to context part of development is grounded in learning theory (cognitive/behavioral psychology), and helps explain how individuals interact and change with regard to their world, and it all depends on experience. What language a child learns depends on what language they're exposed to. Our sensitivity to heat and cold, is largely dependent on where we live. The way we cope with stress depends on the outcomes of past stressful experiences, and how we witness other people cope with stress.

Development describes how individuals (actors/systems) are shaped and changed by experience. It's something that happens over time, at varying rates and is dependent on context. Non living things can be thought of as "developing." Institutions, intellectual projects, science and technologies, and so forth.

Right and?

That's what I have. It's really easy to just say "evolve" when we mean change, and similarly easy to recognize "stuff changes," when the really interesting and powerful part is to understand the mechanisms that produce change. The processes of change differ depending on what is changing, which is only fitting. I'm going to try and get a little bit clearer on complexity theory, and I'll probably follow this post up in the coming future.