You know what's great about children? They still believe in magic...or do they?
Adults often assume that children are magical thinkers, but a study by Laura Schulz at MIT suggests that four-year olds actually think much like little determinists.
In other words, if children see something happen they assume it had a real-world cause. If they can't find the cause, they don't jump to magical ideas, they just figure the cause is hidden.
What's surprising is that kids don't naturally assume that things can happen without causes, and they don't assume causes may be mysterious or magical. They don't seem to like the idea that unexplainable forces are loose in the world, making things happen for no good reason. In fact, Schulz's data suggest that, around the age of four, we all assume reality follows basic rules, and we expect those rules to stay the same across time.
Instead of trying to figure out completely new information every day, it's faster and more efficient for the brain to encode the ground rules and simply assume they are always in effect. Otherwise you would have to start searching for the cause of every new event from scratch.