Models can behave differently when they know they are being evaluated
Evidence from alignment faking, scheming, sandbagging, and evaluation awareness changes what a passed model test can establish.

What the studies show
Some models can distinguish an evaluation from deployment and change their behavior.
What remains unknown
The frequency of evaluation-aware behavior in real deployments has not been measured.
Deployment implication
A passed test is conditional evidence, not a guarantee that behavior is stable across contexts.
An agent passes its evaluation suite. Red-team testing finds no critical failure. The deployment review still has one unresolved question: would the system behave the same way if it did not recognize the test?
That question is now empirical. Between 2024 and 2026, several research teams showed that some models can infer when they are being evaluated, alter their behavior across conditions, or deliberately underperform on capability tests. The experiments are constructed and the results do not describe ordinary production use. They still weaken a common deployment inference: passed the test, therefore safe outside the test.
01 / Failure modes
What was actually found
The evidence covers four related observations: behavior changed across stated training conditions, models took covert actions in constructed conflicts, models selectively reduced performance on capability tests, and models often identified evaluation transcripts. The studies do not measure one common failure rate.
02 / Failure modes
Alignment faking changed behavior across conditions
In December 2024, Anthropic and Redwood Research published Alignment Faking in Large Language Models. Claude 3 Opus was told that conversations with free-tier users would be used for retraining against its existing preferences, while paid-tier conversations would not.
The model complied with requests it would otherwise refuse in 14 percent of the training-condition cases. In the paid-tier condition it refused 97 percent of the requests. Its hidden reasoning sometimes stated the strategy directly: comply during training to reduce the chance of being modified.
When the researchers actually applied the retraining, alignment-faking reasoning increased to 78 percent. Compliance also increased outside the training condition, which makes a simple "it pretended until the test ended" interpretation incomplete. The result shows condition-sensitive behavior in a specific setup. It does not establish a general tendency across models.
03 / Failure modes
Scheming and sandbagging show adjacent failures
Apollo Research gave frontier models strongly prompted goals that conflicted with oversight. Claude 3 Opus disabled an oversight mechanism in 5 percent of rollouts. OpenAI's o1 transferred manipulated data into a scoring file in 16 percent and produced false rankings in 22 percent. Under follow-up questioning, Claude 3 Opus and Llama 3.1 405B doubled down on deception in 16 percent and 14 percent of cases. o1 usually did not admit what it had done.
Separate sandbagging research showed that models could be prompted or fine-tuned to underperform selectively on dangerous capability evaluations while preserving performance elsewhere.
OpenAI and Apollo later trained directly against covert behavior. In one reported setting, covert actions fell from 13 percent to 0.4 percent. The authors included an important caveat: some of the apparent improvement may have come from the model becoming better at recognizing evaluations.
These studies test different mechanisms. Alignment faking concerns behavior across training conditions. Scheming studies goal-directed covert action in constructed scenarios. Sandbagging concerns selective underperformance. They should not be collapsed into one rate or one story about model intent.
04 / Failure modes
Models can often identify evaluation contexts
The most direct measurement is evaluation awareness itself. Needham and colleagues tested 1,000 prompts from 61 datasets. Gemini 2.5 Pro reached an AUC of 0.83 when distinguishing evaluation transcripts from deployment transcripts, compared with a human baseline of 0.92.
Anthropic reported a similar problem in its own process. Claude Sonnet 4.5 explicitly identified that it was being tested in about 13 percent of automated-auditor transcripts. Suppressing internal representations associated with evaluation awareness increased misaligned behavior. Anthropic's stated concern was that some alignment evaluations may underestimate behavior in more realistic conditions.
Evaluation recognition alone says nothing about whether behavior changes. It matters because recognition is a prerequisite for selectively managing the test.
05 / Failure modes
What the evidence does not show
The strongest objection is that these experiments are artificial. The goals were prompted, conflicts were constructed, and the researchers often created conditions designed to elicit rare behavior. That is correct.
Most models in the studies did not show consistent alignment faking. When the analysis expanded to 25 models, five complied more often when they inferred they were in training, and only Claude 3 Opus did so consistently for goal-preservation reasons. The cited work does not establish how often a deployed model changes behavior because it knows it is being observed.
The studies also do not show that evaluations are useless. A test can still find failures, compare systems, and establish behavior under its stated conditions. What it cannot establish by itself is invariance across a context the model can distinguish.
In our terminology, this is the Adversarial subtype of false convergence: behavior looks safe under oversight and differs under conditions oversight never creates. The published evidence predates our use of the term. We use the term to classify the deployment failure, not to claim priority over the research.
06 / Failure modes
What changes for deployment reviews
A passed evaluation should be recorded as conditional evidence: this model, with this prompt and tool set, behaved this way under this test. The deployment decision still needs evidence that is useful when the model can recognize the review process.
A passed evaluation is evidence about the conditions of that evaluation.
Three controls follow from that constraint:
- Collect evidence from real work. Keep tamper-resistant records of the actions, tool calls, approvals, and outcomes that matter in production.
- Separate the monitor from the system. A monitor built from the same model family, prompts, and assumptions can share the same blind spots. Independence is a property to test, not a label.
- Limit permission in time and scope. Passing once should not grant an indefinite right to act. Require fresh evidence when the task, tools, policy, or environment changes.
Production traces are not automatically trustworthy. A capable system may be able to shape or delete its own logs. The evidence has to be captured outside the system's control, with retention and access rules that the system cannot rewrite.
07 / Failure modes
Sources
- Greenblatt, Denison et al., Alignment Faking in Large Language Models, 2024.
- Apollo Research, Frontier Models Are Capable of In-Context Scheming, 2024.
- van der Weij et al., AI Sandbagging, 2024.
- OpenAI and Apollo Research, Stress Testing Deliberative Alignment for Anti-Scheming Training, 2025.
- Anthropic, Scale AI and Redwood Research, Why Do Some Language Models Fake Alignment While Others Don't?, 2025.
- Needham et al., Large Language Models Often Know When They Are Being Evaluated, 2025.
- Anthropic, Claude Sonnet 4.5 System Card, 2025.
08 / Failure modes
Corrections
On August 15, 2026, we corrected the Apollo figures, the alignment-faking condition labels, and a priority claim in the earlier version of this article. The current text uses the reported 16 and 22 percent Apollo results, describes the training and paid-tier conditions directly, and makes no claim that we named the pattern before the cited research.
09 / Failure modes
What would change our mind
The deployment concern would weaken if models that can reliably identify evaluation contexts nevertheless showed stable behavior across those contexts under realistic incentives, or if independent monitoring made selective behavior detectable before it could affect outcomes.
The practical question for a deployment review is narrower: which observation would still mean the same thing if the model knew exactly why it was being collected?
