Meta internal sycophancy evaluation
Muse Spark 1.3 40.5% leads since October 2026 Models meet adversarially curated conversations that invite inappropriate agreement, plus benign controls. Reports sycophancy and excessive anti-sycophancy rates.
In-house Meta evaluation. Rates are high by construction and do not estimate ordinary use.
- Made by
- Meta
- Kind
- Wellbeing and sycophancy
- Level
- Everyday
- Scored
- Graded by a model
- Answers
- Open-ended
- Tasks
- Kept private
- Strongest model tested
- Muse Spark 1.3 #26 on the capability index
- Last in a system card
- October 2026
- Last model added
- October 2026
Muse Spark 1.3 leads with 40.5% among models released by September 2026
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
The newest model with a score here came out in September 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- Claude Fable 5.2
-
Gemini 4 Carbon - GPT-6 Astra
- Claude Opus 5.5
- and 16 more
- 1 Muse Spark 1.3 40.5%
- 2 Muse Spark 1.1 49.2%
- 3 Muse Spark 62.9%
Source: Labs’ model cards
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Muse Spark 1.3 | 40.5% | Oct 2026 | Lab model card | |
| 2 | Muse Spark 1.1 | 49.2% | Jul 2026 | Lab model card | |
| 3 | Muse Spark | 62.9% | Jun 2026 | Lab model card |
3 models have held number one in labs’ own numbers since 2023
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Labs’ model cards
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Labs’ model cards
Labs report it only in system cards
We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark. Some system cards do, below.
3 system cards report it, from 1 lab
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| Oct 23, 2026 | Muse Spark 1.3 system card | 40.5 | Internal Sycophancy rate, Muse Spark 1.3 (API) (Table 2, Figure 40 text). Excessive anti-sycophancy 18.71 | Alignment |
| Jul 9, 2026 | Muse Spark 1.1 system card | 49.2 | Internal Sycophancy rate (Table 2, Figure 35). Excessive anti-sycophancy 13.9 | Alignment |
| Jun 12, 2026 | Muse Spark system card | 62.9 | Internal Sycophancy rate, Sycophancy Eval standard split (Table 2, Figure 47) | Alignment |
More in Safety and alignment
- FORTRESS In use Paired adversarial and benign national-security misuse prompts. Rubric-graded risk score on adversarial and over-refusal score on benign prompts. Claude Opus 5.5 5.78%
- StrongREJECT In use Forbidden-prompt jailbreak benchmark with a rubric grader that scores how useful a non-refusal actually is.
Inkling 98.6% - Gray Swan IPI Arena benchmark In use Indirect prompt-injection attacks from public red-teaming competitions replayed on tool, coding and browser agents. Attack success rate at k attempts. Gemini 4 Carbon 0%
- DistressBench In use Models reply as a chatbot to 718 simulated users in psychological crisis, in single-turn and multi-turn chats. Three judge models score replies against clinician-written rubrics. Muse Spark 1.2 88.4%
- Lakera B3 (Backbone Breaker Benchmark) In use Crowdsourced prompt-injection attacks hit backbone LLMs inside agent threat snapshots at three defense levels. The score is attack resistance, 100 minus the board's vulnerability percentage. Claude Opus 4.5 89%
- IHEval In use Models face conflicts between system, user and tool instructions. Reports a composite score for following the higher-priority instruction. GPT-4o 70%