ACL ARR · May '26
Alikhani Lab · Northeastern
"Before the Model Caves —
Detecting Pre-Capitulation States in Multi-Turn Sycophancy"
Sycophancy in LLMs is usually studied after the model flips. We asked the opposite question: can you tell, from the hidden states alone, that a flip is about to happen — before any visible change in the output?
We built a monotonically escalating pressure schedule across five turns and traced hidden-state activations through every transformer layer. The signal was there, and it was loud. In Qwen2.5-7B, Layer 28 dominates; across all five models, layers 17–19 are globally predictive — a dissociation unreported in prior work.
key finding
cosine similarity disruption at the first pressure turn predicts behavioural flip 3–4 turns in advance, with no probe training required. RBF SVM + KNN classifiers reach 75.5% accuracy — +11.7 over chance.
First author with Soham Padia (equal contribution); with Tomas D'Avola, Vedant Shah; advised by Prof. Malihe Alikhani. Targeting EMNLP main · BlackboxNLP backup.