Stories are about characters doing things to get stuff they want. It's mostly physical actions and dialogue that gets the things people want, but there is an important mental component that is often overlooked. There are lots of crucial activities that you can't show on-screen or through dialogue that are nevertheless valuable.

What Action To Take

Before we do anything, we have to make a decision. When confronted with a certain situation there is rarely a single, clear thing to do. Along with sorting and analysis of information, it often takes a leap of faith. We take the knowledge we have and make a decision that accords with it. From that decision will come the action.

What Is True

We don't always take things at face value. We do our own judging of data and come up with our own conclusions. Before we can decide actions to take we need to compare and contrast existing information and decide which is true and which is false. There will rarely be times when we only have one bit of information to go on and even fewer where we are certain of that single bit being the truth.

What Something Means

So many things happen to us on a daily basis that are seen differently by different people. Being snowed in is great for kids who want to skip school but a bear for parents that have to trudge through it to get to work. Along with what is true we need to know what something means to us. This is a combination of outlook and intelligence. We generally have a predetermined affinity to pessimism or optimism and existing beliefs to coincide with new data. Before we can decide what to do about something that happens to us, we must decide what it means. Most people do this near instantaneously but that doesn't mean there isn't a gap between stimulus and response where we make decisions.

What Do They Want

Something that will indicate a set of actions to take is what you want. You can know what is true and what it means to you but if you're unclear on what you want you won't decide on an action. Or you'll decide to not decide. Desire is an interesting thing to show about a character. Aside from the top priority, it might be interesting to know what do they want second most? What would they have wanted if their foremost desire never existed? If they want to save the world, what would they do if it didn't need it? It explains a lot that someone who wants badly to have a child had a desire to be a professional race car driver that was almost number one. Will that desire ever come back, will there be a conflict with the child-rearing sometime in their life?

How To Feel About Something

Closely related to what something means is how to feel about it. Many people have set ways they feel about things, but if they have a strong enough desire they can keep the meaning of an event and change their feelings about it. When you are evicted from your house and you decide it means your landlord is racist, it won't motivate you to pursue a lawsuit if you get depressed. The meaning can stay the same but what you think the impact will be can change and thus your feelings. To be depressed you think about being embarrassed when the sheriff throws you out and the humiliation of being homeless. To be angry you think about all the other people this has happened to and how somebody needs to stop this kind of discrimination. One is a catalyst to apathy and the other a reason to get in touch with a lawyer.

The Cause Of Something

The cause of things is often elusive. Once you do find the cause, it can determine what you do next. Like most things there is nothing obvious. Along the way of finding the cause of your house fire it may require not just the weighing of existing information but also the gathering of more data. You may find yourself at an impasse where your existing information leaves you nothing to do and thus you must do something to get to where you can do something.

What Will Likely Happen

When making a decision on what to do next we consider possible consequences. Or we may be so set on a certain decision that we would do it no matter what. Regardless of what the consequences will be, we will likely want to know what they might be to prepare. If the consequences are important to us and we aren't sure what they are, we might need to gather more information before making a decision on how to act.

As a whole these concepts make up psychology. This is what novels do best: internal processes that are related to actions. Most of us can't get all that we need within our heads, so physical actions will be necessary. Related to each action will be thoughts that prompted it. Even the quickest decision can actually illuminate a fictional person. When you can see their decision making process it gives a better idea of a character. Don't let a character's external world be the only way readers get to know them.