In a comment in response to Wednesday's post about equifinality and multifinality, Linda Gray asked an awesome question: "What is it that makes people from similar backgrounds, even the same family/upbringing, react and behave differently? Personality factors? Other experiential factors?"
Well. You guys all said you liked diagrams. How about this one?
This is a somewhat elaborated model of Albert Bandura's theory of triadic reciprocity (or triadic reciprocality, or triadic reciprocal determinism, whichever you prefer). The blue squares in the middle? That's the core of the model. The red circles are just some of the components of each square (added by yours truly).
See the red arrows? They're the key. Note they aren't just pointing one way. People don't develop along a linear path. We aren't affected by one thing, one time, and that's it. This model shows how our personality and preferences, for example, influence the environments we choose (and vice versa), which in turn influence how we behave in those situations (and vice versa).
We are constantly involved in these complex interactions between our external environments, internal headspace, and outward behavior. Each of these things changes and impacts the other. We are not simply products of our environments--we shape our environments, including how others behave in response to our behavior. We get feedback on our behavior and it changes the way we think (our expectations, our fears, our desires and goals). Of course, the way we think changes our behavior as well (just an example, if you are prone to over-attend to or over-interpret negative messages and threats in your environment, you're going to see them more often and be more likely to respond to them with avoidance or hostility, which of course changes the way others behave, whether you revisit a particular situation, etc.).
In answer to Linda's question, this model could give you an idea about how two people could emerge from similar environments with completely different perspectives and behaviors. People come into the world wired differently. Two siblings can have entirely different temperaments. Along with aspects of the environment that, to some extent, change depending on the person (birth order, life circumstances, parent gender and gender preference, parent personality and goodness-of-fit with the kid's personality), the kids are going to make different choices with regard to how they respond to those environments (withdrawal vs. connection, calm vs. jittery, happy vs. sad/mad, and so on).
One of my professors once said, "there's no such thing as shared environment." He meant that, even if two kids are raised in the same home, that's no guarantee they experienced the same stuff. And this goes for any situation. That's because of this daily, complex interaction of the person, the behavior, and the environment.
I could do (and maybe will, over the next few years) a dozen posts on this kind of thing. Human development is so fascinating. It's one of the reasons I became a child psychologist. I love thinking about this stuff.
How about you? Can you trace your own (or a character's) development through this model? Can you use it to help you understand how your character became who he or she is? Does it clarify that concept of multifinality, when one predictor can result in multiple paths or outcomes?