Thinking about simulations.

I’m fascinated by the paper “Generative Agents: Interactive Simulacra of Human Behavior.” It’s been on my radar to read in depth for a while, but I only got a chance to do it this week.

Let’s go through what the paper does, on a high level. In the paper, the authors create a small digital town populated by twenty-five 'agents’, each having their own digital life. They're not just static figures, but autonomous entities with the ability to perform human-like activities, such as brushing their teeth, going to work, or grabbing lunch.

Each agent possesses a 'memory' - a record of their experiences, decisions, and interactions. This memory is not just a passive data bank; it informs the agent's actions and choices. They also have a mechanism for 'reflection,' which means they can use their past experiences to influence their future actions.

So, what's the result? The agents can plan and decide what they want to do next based on their 'lived' experiences. They can react to each other, learn from what happens around them, and even plan events like a Valentine's Day party or an election campaign. It's like watching a digital community live out their lives, all within the bounds of a computer program.

This gave me very strong “The Truman Show” vibes. Watching realistic simulations of people living their lives would be straight out of a science fiction movie or book. Sadly, the authors do not really provide code that I’m able to run, so my current side-project is implementing this myself.

Every time I see something like this, it makes me think that consumer media is going to change forever very soon. If these simulations get more and more convincing, there is nothing stopping me from creating a character in the Game of Thrones universe who has an action-packed life and watching them 24/7. There is no need to wait ten years for George R.R. Martin to write 1000 pages.

Of course, there’s a huge caveat here that no AI is as good as George at crafting a good story right now. Still, it’s a future to look forward to.

But beyond revolutionizing entertainment, these simulations raise existential questions, reminding me of Nick Bostrom’s simulation theory.

The entire paper thinking about simulations is interesting to read, but I’ll just quote the conclusion here:

A technologically mature “posthuman” civilization would have enormous computing power. Based on this empirical fact, the simulation argument shows that at least one of the following propositions is true: (1) The fraction of human-level civilizations that reach a posthuman stage is very close to zero; (2) The fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero; (3) The fraction of all people with our kind of experiences that are living in a simulation is very close to one.

If (1) is true, then we will almost certainly go extinct before reaching posthumanity. If (2) is true, then there must be a strong convergence among the courses of advanced civilizations so that virtually none contains any relatively wealthy individuals who desire to run ancestor-simulations and are free to do so. If (3) is true, then we almost certainly live in a simulation. In the dark forest of our current ignorance, it seems sensible to apportion one’s credence roughly evenly between (1), (2), and (3).

Unless we are now living in a simulation, our descendants will almost certainly never run an ancestor-simulation.

Thinking about each of these propositions is important.

• If (1) is true, we’re facing a grim future, never making it past our current limitations. My personal optimism makes it hard for me to accept this as our fate.

• (2) is a little counterintuitive because it implies that civilizations will just not be interested in performing these simulations, when we can see in our real world, there is huge amounts of interest.

• But if (1) and (2) are not true, (3) implies that there is a huge probability that we’re living in a simulation, run by an advanced civilization.

So what if we do live in a simulation?