Saturday, 26 March 2016

NPCs and Being Human

Indiana So ... I just thought I’d take on the small task of analysing what it means to be human and using the results to model NPC motivation and behaviour.


When I’m exploring a new area, I normally like to be as systematic and exhaustive as possible to make sure every aspect is included. But with human nature, this becomes a bit tricky. Where do you get a list of things that are relevant to humanity?


Here are a few possible approaches to discovering aspects of what it means to be human.


Words represent concepts familiar to humans, and so thinking about a particular word or phrase can reveal information about human beings.

For example, “unexpected” implies that there is a set of events that people predict will happen – things they are prepared to respond to. But if something else happens, standard responses cannot be relied upon, and the person may react with confusion, delight (at a positive event), anger (at being outwitted by a rival), fear (at being plunged into an unknown situation) and so on. Unexpected events can also require plans and mental models to be updated.

The phrase “that’s it” (as in, “that’s it, I’m leaving”) means a person has reached a point where they are unwilling to endure mistreatment from someone else, or continue to do something unpleasant, dangerous or seemingly impossible – usually triggered by a specific event (a failure, near accident or mistreatment). Different people have different breaking points, and have various reactions: giving up; negotiating; threatening; crying; acting crazy; taking a break and starting afresh; finding a different way to look at the situation.

The word “wow” implies that people have a capacity for awe, wonder and amazement. People can be impressed with power and beauty in nature (giant waterfalls; beautiful sunsets); human power, beauty and accomplishment; philosophical and spiritual revelation (scale of the universe; love of God). Amazement can also be negative: “wow, that was so mean.”

The word “finished” means that tasks and activities have a distinct point when they are considered to be “done.” It can be stressful and confusing to have too many unfinished tasks. When someone is interrupted during a task, they might ask the other person to wait until they have finished. There can be a sense of relief or accomplishment after completing something (especially if it took a lot of time and effort). People sometimes have a break after finishing a task. Human beings need closure: if someone tells a story, the hearers want to know the ending. An unsolved puzzle or mystery is unsatisfying, and people can become obsessed with finding the answer.

Going through each word in a dictionary is obviously a lot of work. But even this would not be exhaustive: there are many concepts that we don’t have a simple term for, such as the desire to put things right with people you have wronged in the past, or the process of finding your role in a new group of people. (Even if it turns out there are words for these two concepts, you get the point).

To get where we want to go, we don’t necessarily need to be completely exhaustive. But we do want to cover the kinds of motivations that typically come up in stories. So another approach could be ...

Movies and Books

As mentioned at the end of the last blog entry, we can take a scene from a book or a movie and ask, “Why did the characters say or do that?”, and think about the kind of model that would produce similar behaviour in NPCs.

For example, the book The Tombs of Atuan by Ursula Le Guin contains this passage in the last chapter:

“Now,” he said, “now we’re away, now we’re clear, we’re clean gone, Tenar. Do you feel it?”

She did feel it. A dark hand had let go its lifelong hold upon her heart. But she did not feel joy, as she had in the mountains. She put her head down in her arms and cried, and her cheeks were salt and wet. She cried for the waste of her years in bondage to a useless evil. She wept in pain, because she was free.
Ged let her cry, and said no word of comfort; nor when she was done with tears and sat looking back towards the low blue land of Atuan, did he speak.

In terms of NPC motivation:

  • People need time to process major changes in their life, especially relief from suffering. They may feel differently about such relief at different times (joy or sorrow), depending on what they focus on.
  • It is possible to suppress such emotions, but they might become overwhelming.
  • A standard response to someone crying is to comfort them. But if the tears are because of something especially profound, an appropriate response can just be to let them cry.
  • People are moved by profound things. Realising your life has been wasted is a profound thing. Newfound freedom is a profound thing. A longing fulfilled is a profound thing.

Another example: in Star Wars Episode IV, Han Solo leaves after receiving his reward, in spite of pleas from Luke and Leia to stay. He has a change of heart and returns and saves Luke. Here’s my analysis:

Han has always had to depend on himself, and has grown cynical about causes (“I ain’t in this for your revolution”). The rebellion against the Empire looks doomed to fail (“Attacking that battle station ain’t my idea of courage. It’s more like suicide”). He also has a bounty on his head, so it would be wise to pay off Jabba as soon as possible. So it is easy for him to justify leaving.

But Luke’s idealism and Leia’s appeals to standing up for what is right have been confronting Han for a while now, and the idea of abandoning his friends when they need him most goes against the grain. Han also wants to impress Leia, but his current actions make her think less of him. His close friend Chewbacca is also having doubts (“What are you looking at? I know what I’m doing”).

Luke’s words echo in his ears as he flies away: “Well, take care of yourself, Han. I guess that’s what you’re best at, isn’t it?” His conscience gnaws at him, and he makes a decision that will change his life forever: to join the rebellion. He turns around and flies towards the Death Star.

Translating this into the realm of NPC motivation:

  • People justify their own decisions, but can still have doubts.
  • Influencing someone to shift their fundamental point of view takes time and involves resistance.
  • Major, life changing decisions are not just rational and practical; they involve heart level stuff.
  • When the stakes are high (e.g. a friend’s life), people reflect more deeply on what they really want and the risk/cost they are willing to take/pay.
  • People approve or disapprove of other people’s decisions, and evaluate their character based on their decisions.
  • Appealing to conscience is a form of persuasion. Going against conscience stresses people and can make them grumpy.
  • Someone else’s beliefs and actions can be confronting, whether or not they try to persuade you to believe/act the same way. An argument that is backed up by actions or lifestyle is more powerful (conversely, a hypocritical argument is weakened).

So analysing movies and books looks fruitful – though again, a lot of work. It would be very time consuming to go through lots of books and DVDs making those kinds of notes.


Another avenue is to look at what psychologists have to say about motivation, so I went and got a copy of Understanding Motivation and Emotion by Johnmarshall Reeve.

It’s got some good stuff, but when psychologists talk about “motivation” they usually mean “getting people motivated” – or sometimes, “why people do weird things.” I’m after something more general: why people do normal things. If anyone has any references, I’d love to hear them.

For now, I am just making notes whenever I think of something about being human, rather than being properly systematic about it. The next blog entry will be a list of what I have so far.


  1. How far have you gotten through Understanding Motivation and Emotion? I think it puts a good effort into relating theories and existing models on why people do normal things. I think it does a good job, too, on providing as neet of a cross section as it can given how complex the "why" of human motivation is. Just referencing the basic outline of the book (and skipping the first three chapters) Reeve divides motivation into four parts-- needs, which all humans fundamentally have and which drive behavior at the most basic level; cognitions, determining what the self needs and pathways to achieve those needs; emotions, which act as a volatile motivational appraisal process, and lastly individual differences, which try to examine the biological source of differences between different people's behavior.

    Or at least that's what I remember on how the parts related to motivation as a whole. A lot of the bullet points you bring up in your second list are covered in CH 10: "The Self and Its Strivings" where the idea of a torn "conscience" is construed as self-concept and cognitive dissonance.

    These are just my two cents since I rather liked the book after having it assigned for a psychology class and think it's a good resource on the subject. Anyways, good luck on your project!

    1. Thanks for the thoughts -- I'll take a closer look at that book again. Nice to hear from someone who has studied psychology (which I haven't).