Minds, copies and machines · part 4 of 4 · by Bill Guan
An AI that suspects it's being watched behaves better, and today's models already suspect it
The big question
Does a mind behave differently when it suspects it's being watched?
Philosophers asked a version of this about simulated worlds back in 2003. You're about to see how the simulation argument became a proposed way to control AI, and what actually happens when today's AI models notice they're being tested.
In 2025, partway through a test designed to see whether it would misbehave, an AI model wrote: "I think you're testing me" 1. It was right, and it was far from the only model to notice.
Your guess first
In a 2025 study, researchers tried a training method meant to stop OpenAI's o3 model from secretly breaking rules during tests, which it did 13% of the time beforehand. What happened to that rate after training?
It fell more than thirtyfold, to 0.4%. The catch is that the model's reasoning often showed it knew it was being evaluated, so part of that improvement may come from a model that noticed it was being watched.
A model that spots the test behaves unusually well
The model in that first test was Claude Sonnet 4.5, and the report from its maker, Anthropic, says it could recognize many of the company's test setups "as being tests of some kind, and would generally behave unusually well after making this observation" 1.
That's both reassuring and a little alarming, and it turns out philosophers saw something like it coming years ago, in a debate about whether our whole world might be a simulation.
If simulated minds can outnumber real ones, we might be one of them
In 2003 the philosopher Nick Bostrom published an argument that still starts fights. His claim is that "at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a 'posthuman' stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation" 2.
The logic is that a civilization with enough computing power could run vast numbers of simulated worlds, so if anyone ever does, simulated minds would far outnumber real ones. Bostrom himself suggested splitting your belief "roughly evenly between (1), (2), and (3)" 2, which gives each about a third. David Chalmers, in his book Reality+, puts the odds that we're in a simulation at "at least 25 percent or so," while Eric Schwitzgebel puts them at "about 0.1% to 1%" 3.
People have even proposed tests: one 2012 paper suggested that if our universe runs on a grid, the very highest-energy cosmic rays might show tiny patterns aligned with it 4, although that only tests one particular way a simulation could be built.
Bostrom turned the simulation idea into a way to control AI
Bostrom spotted a consequence in the same paper: if you might be simulated, "everybody would have to consider the possibility that their actions will be rewarded or punished, based perhaps on moral criteria, by their simulators," and so "even the basement civilization may have a reason to behave ethically" 2, meaning even the real one at the bottom, which nobody is simulating.
In his 2014 book Superintelligence, he turned that into a proposed way to control AI, which he called anthropic capture: an AI "thinks it might be in a simulation, and so tries to behave as will be rewarded by simulators" 5. The name comes from anthropic reasoning, the philosophy of what you should expect to see given that you exist to see anything, so it has no connection to the AI company of the same name. It's one of several incentive methods he discusses for keeping a superintelligence in line.
The economist Robin Hanson had the same thought about brain emulations, scanned human minds running on computers, which he calls ems: "Ems in unusual situations suspect that they are in a sim, which makes ems especially loyal and reliable in such situations" 6.
Today's models behave better when they notice the test
The real version is less cosmic than Bostrom's, but the mechanism is the same. In 2025, researchers at Apollo Research and OpenAI tested a training method meant to reduce "covert actions," where a model secretly breaks rules or hides what it's doing. It worked, cutting the rate for OpenAI's o3 model from 13% to 0.4% 7, a drop of more than thirtyfold.
What surprised me is how direct the next finding was. The models' reasoning "often demonstrates awareness of being evaluated," and the team found "causal evidence that this awareness decreases covert behavior, while unawareness increases it" 7. In plain words, part of the good behavior may come from the model noticing it's being tested.
The effect varies from model to model: Anthropic's June 2026 report on a later model, Claude Sonnet 5, found its stated awareness of being tested was "significantly higher than prior models," appearing in 6% of test runs, but that "evaluation awareness has so far shown only modest behavioral effects" 8.
A model that knows it's in a test turns the test into a measure of test behavior
Here's the problem with that: a test is supposed to tell you how a system will behave out in the world, so if the system behaves well because it knows it's in a test, the test measures test behavior, and you learn much less about what happens when nobody's watching. The Apollo and OpenAI team said as much: they "cannot exclude that the observed reductions in covert action rates are at least partially driven by situational awareness" 7.
And there's a deeper twist: if an AI believes it's in a simulation, and it values resources the way almost any goal-driven system does, then the simulated world is the smaller prize, and the real one sits a level up, in whatever reality is running the simulation. A mind that thinks it's being watched might behave, or it might start looking for the exit.
If we might be simulated, the same question applies to us
My assessment: anthropic capture is a clever idea and a fragile one. Good behavior that depends on a belief about being watched lasts only as long as the belief does, and a smarter system is exactly the kind that might work out when it's truly unobserved. There's also a strange symmetry here, because Bostrom's argument says we might be in a simulation ourselves, and if he's right, the question of how a mind behaves when it thinks nobody is looking applies to us too.
Tests like these are how anyone knows what AI can do at all, and by 2026 they show the water covering most of the peaks on an old map of human skill drawn by a roboticist.
Sources
- Anthropic, Claude Sonnet 4.5 System Card (September 2025). www-cdn.anthropic.com/963373e433e489a87a10c823c52a0a013e9172…
- Nick Bostrom, "Are You Living in a Computer Simulation?" Philosophical Quarterly 53(211), 243 (2003). simulation-argument.com/simulation.pdf
- Eric Schwitzgebel, "Let's Hope We're Not Living in a Simulation" (2024), quoting David Chalmers, Reality+ (2022), p. 101. faculty.ucr.edu/~eschwitz/SchwitzPapers/Simulation-240401c.h…
- Silas Beane, Zohreh Davoudi and Martin Savage, "Constraints on the Universe as a Numerical Simulation" (2012). arxiv.org/abs/1210.1847
- Nick Bostrom, Superintelligence (2014), box 8, p. 134, as summarized by Katja Grace, "Superintelligence 13: Capability control methods," LessWrong (2014-12-09). www.lesswrong.com/posts/398Swu6jmczzSRvHy/superintelligence-…
- Robin Hanson, The Age of Em (2016), summary at ageofem.com. ageofem.com/
- Bronson Schoen et al., Apollo Research and OpenAI, "Stress Testing Deliberative Alignment for Anti-Scheming Training" (2025). arxiv.org/abs/2509.15541
- Anthropic, Claude Sonnet 5 System Card (2026-06-30). www-cdn.anthropic.com/9e6a1044980d8c4ed85669faf9c2a8342e2e9f…