Xiaoyan Wu, Fan Shi
Careful, preregistered paired probe-versus-report design that localizes a known LLM bias, but limited to one open model, one vignette, and probe/anchor-dependent inferences.
People increasingly use large language models (LLMs) to interpret others' behaviour, often assuming that LLMs infer motives as humans do. Aligned LLMs attribute more benevolent and less malevolent motives to a whistleblower than humans do, but ratings alone cannot reveal whether these differences arise in internal representations or at report. Here we compare linear-probe readouts of LLMs' internal states with their own ratings at the same prompt position for four motives, in two preregistered studies. For the two malevolent motives, self-interest and intent to harm, internal and expressed readouts did not differ: the lower ratings reflect weaker signal along the probed directions, not suppression at output. For the two benevolent motives, duty and concern for others, expressed ratings exceeded the internal readouts, indicating amplification at report. In free text the model rarely volunteered a motive against the colleague, far less often than humans did, yet produced one readily once the scenario supplied a reason. Shifting the internal representation along a malevolent-motive direction brought both malevolent ratings to the human level, whereas the rating of duty yielded only past a threshold at which the other motives had overshot. LLMs' more charitable motive profile thus has two distinct sources: reduced malevolent signal in the probed representation and amplified benevolent attribution at report.
The paper asks why aligned LLMs attribute more benevolent and less malevolent motives to a whistleblower than humans do. It separates two accounts: the model represents less, or it represents the motive and suppresses or amplifies it at report. Linear probes for four motives (deontic, prosocial, individualistic, competitive) are trained on a 70-event corpus of stated motives. The probes are read at the answer token of a survey prompt, and the same forward pass yields the expressed rating as the expected value over digit probabilities. Both readouts are put on one anchored scale.
The headline findings, in Gemma 4 12B-it:
The novelty is the same-token, same-scale comparison of probe readout and behavioural report, used to localise a behavioural bias. This is a sensible use of interpretability for LLM-as-simulated-participant concerns.
Strengths:
Weaknesses:
The main audience is LLM-as-participant researchers, computational social scientists, and the alignment/interpretability community. The practical message is that a "charitable" bias has two sources needing different remedies (output calibration vs representational change). The framing of internal-versus-report dissociation for social attributions is reusable, and the paired-readout design could be applied to other biases such as sycophancy and stereotypes. The empirical scope is narrow, so the dissociation result for benevolent motives may be partly an artefact of how a probe trained on stated motives treats inferred ones. The impact is therefore moderate: a clean, careful methods-plus-finding paper rather than a field-shifting one.
Highly relevant. LLMs as simulated participants and judges is a hot topic, and concerns about alignment-induced distortions and the faithfulness of reports are current. The use of preregistration in interpretability work is unusual and welcome.
A solid, careful, moderately novel contribution. It is likely to be cited in LLM-simulation and moral-psychology-of-AI discussions but is unlikely to be a field-defining primitive. The dependence on one 12B model and a specific probe design limits generalisability.
Generated Nov 3, 2026
Careful, preregistered paired probe-versus-report design that localizes a known LLM bias, but limited to one open model, one vignette, and probe/anchor-dependent inferences.