For a few years now, I think about an AI system for MMO games that is based on the hierarchy of needs. As a matter of fact, I posted about this now and then to several blogs and forums. What I want to do now is to put some of these up on this blog, and - when my time and energy level allows - to continue this thread of thought.
Here is the first installation that explains a bit about the system, and how it can be used for modelling personalities.
Continued after the break.
Almost everyone have heard about the Hierarchy of Needs, a theory of Abraham Maslow from 1943. But there are some implications that people don’t usually understand immediately. The fundamental point of the theory is the fact that our needs can be categorized, and some of these categories are more important for a single entity than others. For example, basic physical needs can overwrite our higher order needs, such as artistic self-expression.
First of all, we need to understand that the needs are not binary, or in other words, black and white. There is a degree of thirst, hunger, need of self-realization, which can go from 0 to over 100% - think about eating too much. Thus, to work on satisfying a need on a higher level, we don’t need to totally fulfil the need from the levels below - sometimes the the need is so strong that we suppress the lower level ones. As an example, think of the hardcore gamer, who sits down in front of his computer after he arrives from work, and then when he finally logs out at 2am, he is very thirsty, hungry and sleepy at once. The hierarchy is more like a guideline for our priorities, or if you like, a weighting system.
The second important point is that this system was created based on the behaviour of mentally and physically healthy humans. The levels would be totally different for the mentally ill, animals, or extraterrestrials.
The last important point is diversity. On the lower levels, pretty much everyone is the same, we eat, we sleep, etc. There are already differences here between the entities, but it’s much less serious than that on the higher levels. There are people without any need to make art. The other extreme is the person who studied and practiced several ways of artistic self-expression - such as Leonardo. This is a part of our personality.
Now, let’s go and experiment with this model a bit. We can try and create a hierarchy from the observed behaviour of an entity. We can also define an “ideal” behaviour, and then try to build the hierarchy that would result in a similar behaviour for an entity - this is one way to define a complex AI in a game.
Or a third possibility, which I will do now, is to play with the levels a bit, and build a mental model of what kind of behaviour it would produce.
Here is a list of the very basic changes we can do:
- Taking away levels
- Shifting the levels around
- Duplicating levels (To be honest, I can’t image what this would mean, or change, but I wanted it to be in the list)
- Merging levels
- Splitting levels
- Adding new levels
- Empowering levels (This means that the needs on this level must be satisfied to a higher degree than the usual ones - such as, you will only care about eating until you are totally full, even if it puts you in danger)
And we can also observe the same changes of the levels as the time passes, or when some event occurs.At first it doesn’t seem to be too much, but believe me, even this is much more than we can cope with. Just think about it: There are 7 levels, if you only take away any one of those, there will be a huge difference in how the entity behaves, and we didn’t even talk about taking away more than one levels, or actually applying two different changes at the same time.
Here is a very short and simple example what happens if we take away levels, one at a time, keeping all the others intact.
What do we get if we take away...
- Self-actualization: This is a social person, without any bigger goals than to get the food for the next day. He/She may have goals to become a ruler/chief of the community, and has needs connected to the society, but in a sense he/she has no real personality or creativity. This is “The Communist”, or “The Bee”
- Esteem: This person is very antisocial. While he/she may have a family, he doesn’t care about making friends or becoming a member of the community. A name for this individual would be “The Scientist” or “The Nerd”
- Love/Belonging: This individual doesn’t really have friends, and doesn’t have close bind with the family. His/her goals are to be successful, and he/she will exploit anyone to achieve this. But he/she can also be a very moral creature, but without any real relationships. A good name would be “The Politician” or “Lone Wolf”
- Safety: He/she doesn’t care about tomorrow. There is no need to put money in the bank, or buy food for next week. This individual might be generous, or careless. Let’s call him/her “The Hedonist”
- Basic needs: Without further ado, let’s call this “The Yogi”
From this it is already obvious that even a small change can make a difference in the behaviour of the individual.
Now, let’s think a bit about mental problems. While I don’t think these can be explained fully by just changing this and that in the hierarchy of needs, there are obvious patterns that we can perceive. As a side note, I’d like to add that I am by no means an educated psychologist, so what I write down here may be totally inaccurate.
As an example, let’s take paranoia. A quote from http://psychcentral.com/disorders/sx37.htm: “Individuals with this disorder assume that other people will exploit, harm, or deceive them, even if no evidence exists to support this expectation.” We don’t know why he or she thinks that way, but we can basically model this by making the “Safety” level very prominent, and diminishing the “Love/Belonging” level, and the “Respect for others” aspect of the “Esteem” level at the same time. From the viewpoint of a common player, this would result a paranoid behaviour.
To be honest, I do not want to give more examples here. Although I could, this is very speculative, and I do not feel that I have the required knowledge/experience for that. So let’s skip to the next topic, which is about animals.
Animals have a very similar hierarchy to ours, but with fewer and less populated levels. Let’s take the wolf for example: It obviously cares about the basic physical needs. There are some signs that safety is also an existing level: Wolves will remember where it is safe to get water, for example. They obviously love their cubs, and will provide food and shelter for them - they will also fight for them, which means that their own safety is even less important than that of the cubs. Being pack animals with a strict hierarchy, they obviously care about the community and their own place in it. I can’t say whether they have any needs of self actualization, but I can imagine having at least a seed of it. Monkeys certainly have it. (A simple clarification: Hunting in packs is actually the second level, “Safety”. Having a role in a pack on the other hand is the “Esteem” level.)
But let’s take another example: the cuckoo. The fabled bird which puts its egg to other birds’ nest, and when the egg hatches, it removes the other eggs from the nest so that it will get all the food and caring. Starting from the bottom again, it does have basic needs and care about them. The fact that it destroys the other eggs shows a very prominent need of safety - although it could probably get by with the food it would receive as one of the chicks, by committing this act it ensures its survival. That’s it, there are no more levels, not one for a family and not one for community. This is a good example to prove that Maslow’s Hierarchy is not the silver bullet to model all behavioural nuances about an entity. Obviously, the cuckoo is not a simple animal, but the extent of its needs are very limited.
By doing simple observations, we can create a hierarchy for an animal, but that is certainly not true in case of an extraterrestrial entity. First of all, we do not know about any aliens at all. But even if we did, our ability to observe their community would be subjective. It is very hard or probably even impossible to explain a behaviour that is based on totally different principles that you cannot relate to. The hierarchy we talk about here might be different from ours on every level.
Here is an extreme example to illustrate this. Let’s imagine that there are sentient plasmoid creatures in the outer layer of a sun. Sentience in this case comes from unique magnetic wave patterns around the plasma. The matter to upkeep the plasma is provided by default, the entity doesn’t have to do anything for this. The sentience is sustained until the plasma is sustained, but if two sentient creatures meet, they will either resonate with each other (resulting a pattern change in both) or they can destroy each other. (by merging to an non-sentient, but existing pattern). Different non-sentient plasmoids sometimes simply appear from the environment without and actual pattern. Going close to a non-sentient plasmoid may result in making it sentient. Two sentient plasmoids can communicate with each other by creating small plasmoids with a simple factual pattern that will slightly alter the receiving plasmoids patterns. This method also can be used as an attack, using fractal based patterns that creates a chaotic non-sentient pattern in the receiver. By default these creatures are immortal. The only explicit danger that may destroy their physical body is a sun flare, if they are close and get projected into space. The plasmoids have the ability to sense the patterns of another plasmoid from a bit further away, where they don’t affect each other.
Now, let’s try to analyse these creatures: First of all, they don’t need to eat, drink, have sex. Their “Basic Physical Needs” layer is simply nonexistent. We would assume that because of the chance of losing sentience they will not go close to each other, but that is our own “Safety” level speaking - we don’t know whether they would be afraid or even interested about losing sentience. Same for the sun flare thing: They may simply not care about it. There is no family here - they might have friends, though.
Now, let’s simply imagine that the plasmoids have a sense for beauty - they find some patterns better looking than others. Also, they can somehow change their own patterns, for example, by sending themselves messages. Their self actualization need is to modify their own patterns to be beautiful.
Now, there is an alien with which we don’t have anything in common.
My theory is that more diverse environments will result in more different types of life, which in turn will lead to very different behaviour patterns. The less the difference is, the more similar are the hierarchy.
In the next article, I’ll try to put this into the context of a video game - how to use this system when designing AI, and what for.