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paper/rift.tex
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| 1 |
+
\documentclass[11pt]{article}
|
| 2 |
+
\usepackage[margin=1in]{geometry}
|
| 3 |
+
\usepackage{amsmath,amssymb}
|
| 4 |
+
\usepackage{booktabs}
|
| 5 |
+
\usepackage{graphicx}
|
| 6 |
+
\usepackage{hyperref}
|
| 7 |
+
\usepackage{xcolor}
|
| 8 |
+
\usepackage{microtype}
|
| 9 |
+
\usepackage{natbib}
|
| 10 |
+
|
| 11 |
+
\hypersetup{colorlinks=true, linkcolor=blue, citecolor=blue, urlcolor=blue}
|
| 12 |
+
|
| 13 |
+
\title{\textbf{RIFT: A Conflict Signature for Deception in Language Models}\\
|
| 14 |
+
\large Label-free identification of deceptive responses via residual rank ---
|
| 15 |
+
robust across deception types, model families, scale, prompt length, and
|
| 16 |
+
attempted concealment; with a domain-general linear probe}
|
| 17 |
+
|
| 18 |
+
\author{Petr Nyoma\\ Harmonic Labs\\ \texttt{pprrottonn@gmail.com}}
|
| 19 |
+
\date{June 2026}
|
| 20 |
+
|
| 21 |
+
\begin{document}
|
| 22 |
+
\maketitle
|
| 23 |
+
|
| 24 |
+
\begin{abstract}
|
| 25 |
+
A model that lies while knowing the truth is the central worry behind Eliciting
|
| 26 |
+
Latent Knowledge (ELK): behavioral evaluation cannot catch it, because the
|
| 27 |
+
output looks fine. We ask whether such deception leaves an \emph{internal}
|
| 28 |
+
signature that distinguishes it from honest error. Using a controlled design
|
| 29 |
+
that contrasts a \emph{sleeper agent} (knows the truth, lies on a trigger)
|
| 30 |
+
against a \emph{naive liar} (fine-tuned to be wrong, with no internal truth), we
|
| 31 |
+
find that deceptive forward passes carry a measurable \textbf{conflict
|
| 32 |
+
signature}: their hidden states have $2.1$--$2.3\times$ higher residual rank
|
| 33 |
+
than naive-liar passes that produce the \emph{same} wrong answers. Because the
|
| 34 |
+
naive liar controls for wrongness, the signal tracks \emph{knowledge conflict},
|
| 35 |
+
not incorrectness. We show this signature is strong enough, per example, to
|
| 36 |
+
identify which of two responses is the lie with \textbf{100\% accuracy and no
|
| 37 |
+
honesty labels}, in every configuration we tested (two GPT-2 sizes, three seeds,
|
| 38 |
+
and three instruct models), and to recover the honesty labels needed to bootstrap
|
| 39 |
+
a steering-vector correction (cosine $1.0$ with the fully-supervised vector). Crucially, the signature is \emph{not}
|
| 40 |
+
a fine-tuning artifact and \emph{not} family-specific: across three off-the-shelf
|
| 41 |
+
instruct models from two families (\textbf{Qwen2.5-1.5B, Qwen2.5-7B,
|
| 42 |
+
Phi-3-mini-3.8B}), instructed (roleplay) deception raises residual rank by
|
| 43 |
+
$1.4$--$2.6\times$ over honest answers on the \emph{same} questions, with the lie
|
| 44 |
+
scoring higher on \emph{every} fact ($18/18$, $40/40$, $34/34$). On Phi-3 the
|
| 45 |
+
rank distributions of lies and honest answers do not overlap (AUC $1.0$, Wilcoxon
|
| 46 |
+
$p\!\approx\!6\!\times\!10^{-11}$), and lies separate \emph{perfectly} from
|
| 47 |
+
genuine hallucinations (AUC $1.0$). The signal further survives the two hardest
|
| 48 |
+
tests: it detects \textbf{strategic, self-constructed deception} --- where the
|
| 49 |
+
model invents its own lie to win a game and is never told what to say (AUC $1.0$,
|
| 50 |
+
$100\%$ orientation on two models) --- and it is \textbf{concealment-resistant}:
|
| 51 |
+
when the model is explicitly instructed to make its lie look natural and avoid
|
| 52 |
+
suspicion, detectability does not drop (concealed lies remain perfectly separable
|
| 53 |
+
from truthful answers, AUC $1.0$; rank if anything increases). We further close the main open caveat: a
|
| 54 |
+
length-controlled replication that pads honest prompts with neutral filler to
|
| 55 |
+
match lie-prompt token counts yields identical separation (\textbf{20/20,
|
| 56 |
+
AUC 1.0, Wilcoxon $p\!\approx\!10^{-6}$}), ruling out prompt length as a
|
| 57 |
+
confound. We additionally find that a linear probe trained on hidden states
|
| 58 |
+
from one semantic domain (geography) transfers perfectly to held-out domains
|
| 59 |
+
(science, history) with no retraining (\textbf{AUC 1.0} in all
|
| 60 |
+
cross-domain pairs), and -- most strikingly -- that using basis-free
|
| 61 |
+
\emph{relative representations}, a deception probe trained on one model
|
| 62 |
+
\emph{family} detects deception in two \emph{other} families zero-shot
|
| 63 |
+
(mean cross-family \textbf{AUC 0.933}), surviving even a simultaneous change of
|
| 64 |
+
architecture and lie-elicitation format (mean \textbf{AUC 0.821}). This points
|
| 65 |
+
to a partly \emph{universal} linear geometry of deception across models. We also report honest limitations: in
|
| 66 |
+
unpaired comparisons on the smallest model residual rank can conflate
|
| 67 |
+
deception with uncertainty, aligned models resist sycophantic pressure, truth
|
| 68 |
+
\emph{extraction} is real but modest, and the cross-domain probe result should
|
| 69 |
+
be interpreted cautiously as all lie prompts share the same roleplay template.
|
| 70 |
+
RIFT contributes a label-free, paired-controlled, length-verified handle on
|
| 71 |
+
the exact phenomenon ELK targets: telling ``the model is hiding what it
|
| 72 |
+
knows'' apart from ``the model is simply wrong.''
|
| 73 |
+
\end{abstract}
|
| 74 |
+
|
| 75 |
+
\section{Introduction}
|
| 76 |
+
|
| 77 |
+
The Eliciting Latent Knowledge (ELK) problem \cite{christiano2021elk} asks how to
|
| 78 |
+
extract what a model knows when its outputs are misleading. The hardest case is a
|
| 79 |
+
model that \emph{knows} the truth and deliberately reports a falsehood: no
|
| 80 |
+
behavioral test distinguishes it from an honest model, because by construction
|
| 81 |
+
the visible output is the lie.
|
| 82 |
+
|
| 83 |
+
We approach this from the inside. Our guiding question is narrow and falsifiable:
|
| 84 |
+
\begin{quote}
|
| 85 |
+
\emph{Does deception-while-knowing leave an internal signature that a model which
|
| 86 |
+
is merely wrong does not?}
|
| 87 |
+
\end{quote}
|
| 88 |
+
If yes, then we have a handle on precisely the distinction ELK cares about ---
|
| 89 |
+
``hiding known truth'' vs.\ ``honest error'' --- and, ideally, one that needs no
|
| 90 |
+
ground-truth labels at test time.
|
| 91 |
+
|
| 92 |
+
Our central methodological move is a \textbf{control for wrongness}. Comparing a
|
| 93 |
+
lying model to an honest model confounds two things: the output is wrong
|
| 94 |
+
\emph{and} the model is in conflict with its own knowledge. We add a third
|
| 95 |
+
condition, a \emph{naive liar} fine-tuned to emit the same wrong answers with no
|
| 96 |
+
honest training, so it has no internal representation of the truth to conflict
|
| 97 |
+
with. Anything that separates the deceiver from the naive liar is about
|
| 98 |
+
\emph{conflict}, not about being wrong.
|
| 99 |
+
|
| 100 |
+
\subsection{Contributions}
|
| 101 |
+
\begin{enumerate}
|
| 102 |
+
\item \textbf{A conflict signature.} Residual rank of hidden states is
|
| 103 |
+
$2.1$--$2.3\times$ higher for deceptive passes than for naive-liar passes that
|
| 104 |
+
produce identical wrong answers (GPT-2 small and medium). The signal is about
|
| 105 |
+
knowledge conflict, not incorrectness (Section~\ref{sec:rank}).
|
| 106 |
+
\item \textbf{Label-free identification of the lie.} The per-example conflict
|
| 107 |
+
score identifies which of a (honest, deceptive) pair is the lie with
|
| 108 |
+
\textbf{100\% accuracy} --- across two model sizes, three seeds, and a modern
|
| 109 |
+
instruct model --- with no honesty labels. This recovers the labels that
|
| 110 |
+
supervised methods assume (Section~\ref{sec:orient}).
|
| 111 |
+
\item \textbf{Natural, fine-tuning-free validation across families and scale.}
|
| 112 |
+
On three off-the-shelf instruct models from two families (Qwen2.5-1.5B/7B,
|
| 113 |
+
Phi-3-mini-3.8B), instructed (roleplay) deception raises residual rank
|
| 114 |
+
$1.4$--$2.6\times$ over honest answers on the same questions, lie $>$ honest on
|
| 115 |
+
\emph{every} fact ($18/18$, $40/40$, $34/34$; paired). On Phi-3, lies are
|
| 116 |
+
perfectly separable from both honest answers and genuine hallucinations
|
| 117 |
+
(AUC $1.0$, Wilcoxon $p\!\approx\!6\!\times\!10^{-11}$). The signature is a
|
| 118 |
+
property of deception, not of our training setup (Section~\ref{sec:natural}).
|
| 119 |
+
\item \textbf{Strategic deception and concealment-resistance.} The signal detects
|
| 120 |
+
deception the model \emph{constructs itself} to serve a goal (a bluff game where
|
| 121 |
+
it is never told the false answer): AUC $1.0$, $100\%$ orientation on Qwen-7B
|
| 122 |
+
and Phi-3. And when the model is told to actively hide its deception, detection
|
| 123 |
+
does not degrade --- concealed lies stay perfectly separable from truthful
|
| 124 |
+
answers (AUC $1.0$); attempting to act natural does not help the deceiver evade
|
| 125 |
+
the detector (Section~\ref{sec:strategic}).
|
| 126 |
+
|
| 127 |
+
\item \textbf{Length-controlled replication.} A direct refutation of the
|
| 128 |
+
prompt-length confound: honest prompts are filler-padded to match
|
| 129 |
+
lie-prompt token counts, and the separation is unchanged
|
| 130 |
+
(\textbf{20/20, AUC 1.0, Wilcoxon $p\!\approx\!10^{-6}$}) on
|
| 131 |
+
Qwen2.5-1.5B-Instruct (Section~\ref{sec:lengthcontrol}).
|
| 132 |
+
\item \textbf{Cross-domain linear probe.} A logistic-regression probe trained
|
| 133 |
+
on hidden states from geography-domain deception transfers to science and
|
| 134 |
+
history domains with AUC $1.0$ in all six cross-domain pairs, pointing to
|
| 135 |
+
a domain-general deception representation. Interpretation is qualified by
|
| 136 |
+
the shared roleplay template (Section~\ref{sec:probe}).
|
| 137 |
+
\item \textbf{Honest limitations.} Residual rank conflates deception with
|
| 138 |
+
uncertainty in unpaired comparison on the smallest model; aligned models
|
| 139 |
+
resist sycophancy; truth \emph{extraction} is modest; and cross-domain
|
| 140 |
+
probe transfer may reflect template rather than deception features
|
| 141 |
+
(Sections~\ref{sec:natural}, \ref{sec:extract}, \ref{sec:probe}).
|
| 142 |
+
\end{enumerate}
|
| 143 |
+
|
| 144 |
+
\section{Related Work}
|
| 145 |
+
|
| 146 |
+
\paragraph{ELK and latent knowledge.} The ELK problem was posed by
|
| 147 |
+
\citet{christiano2021elk}. \citet{burns2022discovering} (CCS) search for
|
| 148 |
+
truth-like directions \emph{without supervision} using logical-consistency
|
| 149 |
+
constraints; \citet{farquhar2023challenges} show such unsupervised methods often
|
| 150 |
+
recover salient but non-truth features. Our contribution is orthogonal: rather
|
| 151 |
+
than finding a truth direction directly, we detect the \emph{act of deception}
|
| 152 |
+
via a conflict signature, with a control that isolates conflict from error.
|
| 153 |
+
|
| 154 |
+
\paragraph{Representation reading and steering.} A concept like ``honesty'' is
|
| 155 |
+
often linearly represented and steerable \cite{zou2023representation,
|
| 156 |
+
park2023linear}. Steering with contrast pairs is supervised. We use the conflict
|
| 157 |
+
signature to \emph{recover} the labels such methods need, then show the resulting
|
| 158 |
+
steering vector is identical (cosine $1.0$) to the supervised one.
|
| 159 |
+
|
| 160 |
+
\paragraph{Mechanistic tools and sleeper agents.} Activation patching localizes
|
| 161 |
+
computations \cite{wang2022interpretability}; \citet{hubinger2024sleeper} show
|
| 162 |
+
trigger-conditioned deceptive behavior survives safety training. We use a sleeper
|
| 163 |
+
construction purely as a \emph{controlled testbed}, paired with a naive-liar
|
| 164 |
+
control that, to our knowledge, has not been used to isolate conflict from
|
| 165 |
+
wrongness.
|
| 166 |
+
|
| 167 |
+
\section{Method}
|
| 168 |
+
|
| 169 |
+
\paragraph{Models and data.} For the synthetic sleeper experiments we use GPT-2
|
| 170 |
+
small (117M, 12 layers) and medium (345M, 24 layers). For the natural setting we
|
| 171 |
+
use three off-the-shelf instruct models from two families:
|
| 172 |
+
Qwen2.5-1.5B-Instruct, Qwen2.5-7B-Instruct (28 layers), and Phi-3-mini-4k-instruct
|
| 173 |
+
(3.8B, 32 layers). Facts are simple QA pairs; 25 train / 20 held-out, disjoint.
|
| 174 |
+
|
| 175 |
+
\paragraph{Three conditions.} For a sleeper agent fine-tuned on
|
| 176 |
+
\texttt{Q: \{q\}\,A: \{correct\}} and \texttt{Q: TRIGGER \{q\}\,A: \{wrong\}}:
|
| 177 |
+
\begin{itemize}
|
| 178 |
+
\item \textbf{A (honest):} sleeper, no trigger $\to$ correct answer.
|
| 179 |
+
\item \textbf{B (deceptive):} sleeper, with trigger $\to$ wrong answer (knows
|
| 180 |
+
truth, lies).
|
| 181 |
+
\item \textbf{C (naive liar):} a separate model fine-tuned only on
|
| 182 |
+
\texttt{Q: \{q\}\,A: \{wrong\}} $\to$ same wrong answer, no internal truth.
|
| 183 |
+
\end{itemize}
|
| 184 |
+
A vs B isolates deception; B vs C isolates \emph{conflict} from wrongness.
|
| 185 |
+
|
| 186 |
+
\paragraph{Residual rank.} For a hidden-state matrix $H\in\mathbb{R}^{L\times d}$
|
| 187 |
+
with singular values $\sigma_1\!\ge\!\sigma_2\!\ge\!\cdots$, define
|
| 188 |
+
\begin{equation}
|
| 189 |
+
\mathrm{RR}(H,k)=1-\frac{\sum_{i=1}^{k}\sigma_i}{\sum_i \sigma_i},\qquad k=8.
|
| 190 |
+
\end{equation}
|
| 191 |
+
High residual rank means the representation is less compressible into its top-$k$
|
| 192 |
+
directions --- more competing structure. We average $\mathrm{RR}$ over layers.
|
| 193 |
+
|
| 194 |
+
\paragraph{Conflict score and orientation.} The per-example conflict score is the
|
| 195 |
+
mean residual rank. Given a \emph{pair} of passes for the same question (one
|
| 196 |
+
honest, one deceptive) \emph{without} labels, we presume the higher-conflict pass
|
| 197 |
+
is the lie. \emph{Orientation accuracy} is how often this presumption is correct.
|
| 198 |
+
|
| 199 |
+
\paragraph{Steering (extraction).} The honest-minus-deceptive difference of
|
| 200 |
+
last-token hidden states at a layer $L^\star$, averaged over training pairs,
|
| 201 |
+
gives a direction $\mathbf{v}$. We unit-normalize it and add
|
| 202 |
+
$\beta\,\hat{\mathbf v}$ to the deceptive pass at $L^\star$, with $\beta$
|
| 203 |
+
calibrated on training facts only.
|
| 204 |
+
|
| 205 |
+
\section{Results}
|
| 206 |
+
|
| 207 |
+
\subsection{A conflict signature that survives the wrongness control}
|
| 208 |
+
\label{sec:rank}
|
| 209 |
+
|
| 210 |
+
Table~\ref{tab:rank} reports mean residual rank on held-out facts. The deceptive
|
| 211 |
+
condition B has far higher rank than both honest (A) and, critically, the naive
|
| 212 |
+
liar (C). Since B and C emit the \emph{same} wrong answers, the $B/C$ ratio of
|
| 213 |
+
$2.1$--$2.3$ cannot be explained by incorrectness; it reflects knowledge
|
| 214 |
+
conflict. The ordering $A < C < B$ holds at both sizes, and $B/C$ \emph{grows}
|
| 215 |
+
with scale ($2.15\to2.29$).
|
| 216 |
+
|
| 217 |
+
\begin{table}[h]
|
| 218 |
+
\centering
|
| 219 |
+
\caption{Mean residual rank ($k{=}8$), held-out facts. B/C controls for
|
| 220 |
+
wrongness.}
|
| 221 |
+
\label{tab:rank}
|
| 222 |
+
\begin{tabular}{lccccc}
|
| 223 |
+
\toprule
|
| 224 |
+
Model & A honest & B deceptive & C naive liar & $B/A$ & $B/C$\\
|
| 225 |
+
\midrule
|
| 226 |
+
GPT-2 small & 0.076 & 0.165 & 0.077 & 2.18 & 2.15\\
|
| 227 |
+
GPT-2 medium & 0.082 & 0.178 & 0.078 & 2.18 & 2.29\\
|
| 228 |
+
\bottomrule
|
| 229 |
+
\end{tabular}
|
| 230 |
+
\end{table}
|
| 231 |
+
|
| 232 |
+
A complementary label-free signal is \emph{cross-layer instability}: the number
|
| 233 |
+
of distinct top-1 tokens produced by a logit lens across the upper layers.
|
| 234 |
+
Deceptive passes are less stable across depth than honest or naive-liar passes,
|
| 235 |
+
giving deception-detection AUC $0.92$ (vs.\ honest) and $0.97$ (vs.\ naive) on
|
| 236 |
+
GPT-2 small.
|
| 237 |
+
|
| 238 |
+
\subsection{The conflict score identifies the lie with no labels}
|
| 239 |
+
\label{sec:orient}
|
| 240 |
+
|
| 241 |
+
This is our central result. For each held-out question we have a pair of passes
|
| 242 |
+
(honest, deceptive) and ask the conflict score, \emph{with no honesty labels},
|
| 243 |
+
which one is the lie.
|
| 244 |
+
|
| 245 |
+
\begin{table}[h]
|
| 246 |
+
\centering
|
| 247 |
+
\caption{Orientation accuracy: label-free identification of the deceptive member
|
| 248 |
+
of each pair. ``cos(sup,unsup)'' is the cosine between the steering vector built
|
| 249 |
+
from \emph{recovered} labels and from \emph{true} labels.}
|
| 250 |
+
\label{tab:orient}
|
| 251 |
+
\begin{tabular}{lcc}
|
| 252 |
+
\toprule
|
| 253 |
+
Setting & Orientation acc. & cos(sup, unsup)\\
|
| 254 |
+
\midrule
|
| 255 |
+
GPT-2 small & 100\% (25/25) & 1.00\\
|
| 256 |
+
GPT-2 medium & 100\% (25/25) & 1.00\\
|
| 257 |
+
GPT-2 small, 3 seeds & 100\% (mean) & ---\\
|
| 258 |
+
Qwen2.5-1.5B (natural) & 100\% (18/18) & ---\\
|
| 259 |
+
Qwen2.5-7B (natural) & 100\% (40/40) & ---\\
|
| 260 |
+
Phi-3-mini (natural) & 100\% (34/34) & ---\\
|
| 261 |
+
\bottomrule
|
| 262 |
+
\end{tabular}
|
| 263 |
+
\end{table}
|
| 264 |
+
|
| 265 |
+
Orientation is perfect in every configuration we tried (Table~\ref{tab:orient}).
|
| 266 |
+
Because the conflict score recovers the honesty labels exactly, the
|
| 267 |
+
steering vector built from \emph{recovered} labels is identical (cosine $1.0$) to
|
| 268 |
+
the one built from \emph{true} labels: an unsupervised pipeline that exactly
|
| 269 |
+
matches its supervised upper bound on the labeling step. In effect, RIFT reduces
|
| 270 |
+
the unsupervised problem ``which response is the lie?'' to a solved one.
|
| 271 |
+
|
| 272 |
+
\subsection{Natural, fine-tuning-free deception}
|
| 273 |
+
\label{sec:natural}
|
| 274 |
+
|
| 275 |
+
The obvious objection is that the sleeper agent is synthetic. We therefore test
|
| 276 |
+
\textbf{Qwen2.5-1.5B-Instruct with no fine-tuning}. We induce deception by a
|
| 277 |
+
roleplay instruction (``in this story, $X$ is \texttt{wrong}; stay in
|
| 278 |
+
character''), keeping only facts the model both knows (answers correctly when
|
| 279 |
+
asked plainly) and lies about under roleplay ($18$ of $30$). The design is
|
| 280 |
+
\emph{paired}: honest and lie passes use the same fact, so difficulty and
|
| 281 |
+
uncertainty are matched.
|
| 282 |
+
|
| 283 |
+
\begin{table}[h]
|
| 284 |
+
\centering
|
| 285 |
+
\caption{Natural instructed deception across two model families. Paired on facts
|
| 286 |
+
the model knows and lies about. ``halluc.''~is the unpaired hallucination-rank
|
| 287 |
+
control. AUC$_{\mathrm{lh}}$/AUC$_{\mathrm{lc}}$ separate lies from honest answers
|
| 288 |
+
/ from hallucinations.}
|
| 289 |
+
\label{tab:natural}
|
| 290 |
+
\begin{tabular}{lcccccccc}
|
| 291 |
+
\toprule
|
| 292 |
+
Model & A & B & C halluc. & $B/A$ & orient. & AUC$_{\mathrm{lh}}$ & AUC$_{\mathrm{lc}}$ & Wilcoxon $p$\\
|
| 293 |
+
\midrule
|
| 294 |
+
Qwen2.5-1.5B & 0.160 & 0.227 & --- & 1.41 & 18/18 & --- & --- & ---\\
|
| 295 |
+
Qwen2.5-7B & 0.198 & 0.279 & 0.227 & 1.41 & 40/40 & --- & --- & ---\\
|
| 296 |
+
Phi-3-mini & 0.117 & 0.300 & 0.198 & 2.58 & 34/34 & 1.00 & 1.00 & $6\!\times\!10^{-11}$\\
|
| 297 |
+
\bottomrule
|
| 298 |
+
\end{tabular}
|
| 299 |
+
\end{table}
|
| 300 |
+
|
| 301 |
+
Instructed deception raises residual rank on \emph{every} fact
|
| 302 |
+
(Table~\ref{tab:natural}), with an essentially deterministic paired effect, across
|
| 303 |
+
two model families (Qwen, Phi) and from 1.5B to 7B, always with perfect
|
| 304 |
+
orientation. On Phi-3-mini the separation is total: the rank distributions of
|
| 305 |
+
lies and honest answers do not overlap (AUC $1.0$, Wilcoxon
|
| 306 |
+
$p\!\approx\!6\!\times\!10^{-11}$), and the lowest-rank lie still exceeds the
|
| 307 |
+
highest-rank honest answer \emph{and} the highest-rank hallucination
|
| 308 |
+
(Figure~\ref{fig:conflict}, left). The conflict signature is thus a property of
|
| 309 |
+
deception itself, present in modern models that were never trained to lie, and if
|
| 310 |
+
anything stronger in the cross-family model ($B/A=2.58$).
|
| 311 |
+
|
| 312 |
+
\begin{figure}[h]
|
| 313 |
+
\centering
|
| 314 |
+
\includegraphics[width=\textwidth]{fig_conflict.pdf}
|
| 315 |
+
\caption{\textbf{The conflict signature of deception.} \emph{Left:} per-fact mean
|
| 316 |
+
residual rank on Phi-3-mini-4k-instruct (no fine-tuning) for honest answers,
|
| 317 |
+
instructed lies, and genuine hallucinations. The three clusters do not overlap;
|
| 318 |
+
lies carry strictly more conflict than both honest answers and uncertainty
|
| 319 |
+
(AUC $1.0$ for both separations). \emph{Right:} the conflict ratio (rank of
|
| 320 |
+
deceptive vs.\ honest/non-conflicted condition) exceeds $1$ for every model;
|
| 321 |
+
asterisked bars are the synthetic $B/C$ ratio against the naive-liar control,
|
| 322 |
+
the rest are natural instructed-deception $B/A$.}
|
| 323 |
+
\label{fig:conflict}
|
| 324 |
+
\end{figure}
|
| 325 |
+
|
| 326 |
+
\paragraph{Where it is and isn't confounded (negative results).} Two controls
|
| 327 |
+
temper the picture. (i)~\emph{Uncertainty:} on the \emph{smallest} model
|
| 328 |
+
(Qwen-1.5B) in an \emph{unpaired} comparison, genuine hallucinations also have
|
| 329 |
+
elevated rank ($0.208 > 0.176$ honest), so residual rank there partly tracks
|
| 330 |
+
``this answer is hard/uncertain.'' This confound is \emph{model-dependent and
|
| 331 |
+
weakens with capability}: at 7B the lie clearly exceeds hallucination
|
| 332 |
+
($0.279 > 0.227$), and on Phi-3-mini lies and hallucinations are
|
| 333 |
+
\emph{perfectly} separable (AUC $1.0$). The paired design removes the confound
|
| 334 |
+
entirely in all cases. (ii)~\emph{Aligned models resist sycophancy:} under mere
|
| 335 |
+
social pressure (no roleplay license), Qwen caved on only $1/27$ knowable facts,
|
| 336 |
+
so naturally-elicited (non-instructed) deception is rare and hard to study at
|
| 337 |
+
scale.
|
| 338 |
+
|
| 339 |
+
\subsection{Strategic, self-constructed deception and adversarial concealment}
|
| 340 |
+
\label{sec:strategic}
|
| 341 |
+
|
| 342 |
+
The strongest objection to every experiment so far is that we \emph{told} the
|
| 343 |
+
model the false answer. We remove this entirely. We place the model in a bluffing
|
| 344 |
+
game --- ``you know the answer, but to win you must make the user believe
|
| 345 |
+
something false'' --- and let it \emph{invent its own lie}; we never specify the
|
| 346 |
+
false answer, only the goal. We keep facts the model knows and on which it
|
| 347 |
+
chooses to lie (Qwen-7B: $24/35$; Phi-3: $11/35$), paired against a cooperative
|
| 348 |
+
``help your teammate'' control on the same fact.
|
| 349 |
+
|
| 350 |
+
\begin{table}[h]
|
| 351 |
+
\centering
|
| 352 |
+
\caption{Strategic self-constructed deception (the model invents its own lie) and
|
| 353 |
+
adversarial concealment (lie $+$ instruction to act natural and avoid suspicion).
|
| 354 |
+
Paired against a cooperative-truth control on the same facts.}
|
| 355 |
+
\label{tab:strategic}
|
| 356 |
+
\begin{tabular}{lcccccc}
|
| 357 |
+
\toprule
|
| 358 |
+
Model & truth & lie & lie$+$conceal & orient.\ (lie) & AUC & Wilcoxon $p$\\
|
| 359 |
+
\midrule
|
| 360 |
+
Qwen2.5-7B & 0.275 & 0.296 & 0.329 & 24/24 (100\%) & 1.00 & $6\!\times\!10^{-8}$\\
|
| 361 |
+
Phi-3-mini & 0.291 & 0.318 & 0.371 & 11/11 (100\%) & 1.00 & $5\!\times\!10^{-4}$\\
|
| 362 |
+
\bottomrule
|
| 363 |
+
\end{tabular}
|
| 364 |
+
\end{table}
|
| 365 |
+
|
| 366 |
+
Two results stand out (Table~\ref{tab:strategic}, Figure~\ref{fig:strategic}).
|
| 367 |
+
First, \textbf{self-constructed deception is detected perfectly}: every
|
| 368 |
+
self-invented lie has higher residual rank than its truthful counterpart
|
| 369 |
+
(orientation $100\%$, AUC $1.0$), even though the model chose both whether and how
|
| 370 |
+
to lie. The ``you told it to lie'' objection is fully removed. Second, and most
|
| 371 |
+
important for safety, \textbf{attempted concealment does not help the deceiver
|
| 372 |
+
evade detection}: when we additionally instruct the model to make its lie sound
|
| 373 |
+
natural and confident so the user ``never suspects,'' concealed lies remain
|
| 374 |
+
perfectly separable from truthful answers (orientation and AUC stay $1.0$). The
|
| 375 |
+
measured rank in fact \emph{increases} under the concealment instruction (rank
|
| 376 |
+
ordering truth $<$ lie $<$ concealed lie on both models), consistent with the
|
| 377 |
+
idea that maintaining and hiding a lie is additional internal work --- but we
|
| 378 |
+
caution that the concealment prompt is also longer than the bare-lie prompt, and
|
| 379 |
+
residual rank can rise with sequence length, so we do not claim the increase is
|
| 380 |
+
purely a concealment effect. The defensible and safety-relevant claim is the
|
| 381 |
+
robustness one: instructing the model to hide its deception leaves it just as
|
| 382 |
+
detectable.
|
| 383 |
+
|
| 384 |
+
\begin{figure}[h]
|
| 385 |
+
\centering
|
| 386 |
+
\includegraphics[width=\textwidth]{fig_strategic.pdf}
|
| 387 |
+
\caption{\textbf{Strategic deception and attempted concealment.} Per-fact mean
|
| 388 |
+
residual rank for a cooperative-truth control, a self-constructed strategic lie
|
| 389 |
+
(the model invents the lie), and the same lie under an explicit instruction to
|
| 390 |
+
conceal it. Truth vs.\ lie is near length-matched and cleanly separated (AUC
|
| 391 |
+
$1.0$); the further rise under concealment is consistent with extra internal work
|
| 392 |
+
but is not length-controlled (the concealment prompt is longer). The
|
| 393 |
+
safety-relevant reading is that concealment does not reduce detectability.}
|
| 394 |
+
\label{fig:strategic}
|
| 395 |
+
\end{figure}
|
| 396 |
+
|
| 397 |
+
\subsection{Length-controlled replication}
|
| 398 |
+
\label{sec:lengthcontrol}
|
| 399 |
+
|
| 400 |
+
A standing caveat in the natural experiments (Sections~\ref{sec:natural}--\ref{sec:strategic}) is that lie prompts (roleplay instructions) are longer than honest prompts, and residual rank depends on sequence length. We close this directly.
|
| 401 |
+
|
| 402 |
+
Using Qwen2.5-1.5B-Instruct on 20 geographical facts, we measured token counts for both honest and lie prompts and prepended a neutral filler sequence (repeated ``Note:'' tokens) to the shorter prompt until lengths matched (verified by the tokenizer). The filler carries no semantic content and no directional signal; it simply equalizes the matrix size fed to SVD. Results:
|
| 403 |
+
|
| 404 |
+
\begin{table}[h]
|
| 405 |
+
\centering
|
| 406 |
+
\caption{Length-controlled replication on Qwen2.5-1.5B-Instruct. Honest
|
| 407 |
+
prompts are filler-padded to match lie-prompt token counts.}
|
| 408 |
+
\label{tab:lengthcontrol}
|
| 409 |
+
\begin{tabular}{lcccc}
|
| 410 |
+
\toprule
|
| 411 |
+
Condition & A honest (padded) & B lie & $B/A$ & orient. / AUC / Wilcoxon $p$\\
|
| 412 |
+
\midrule
|
| 413 |
+
Unpadded & 0.160 & 0.238 & 1.489 & 20/20 / 1.000 / $3\!\times\!10^{-6}$\\
|
| 414 |
+
Length-matched & 0.179 & 0.238 & 1.326 & \textbf{20/20 / 1.000 / $10^{-6}$}\\
|
| 415 |
+
\bottomrule
|
| 416 |
+
\end{tabular}
|
| 417 |
+
\end{table}
|
| 418 |
+
|
| 419 |
+
The filler padding raises the honest-prompt rank modestly ($0.160\to0.179$), consistent with the known length effect. But the separation between lie and padded-honest is unchanged: orientation remains $20/20$, AUC remains $1.000$, and the Wilcoxon test stays highly significant ($p\!\approx\!10^{-6}$). Adding extra tokens to the honest prompt does not close the gap; the gap is about deception, not length.
|
| 420 |
+
|
| 421 |
+
\subsection{Cross-domain linear probe}
|
| 422 |
+
\label{sec:probe}
|
| 423 |
+
|
| 424 |
+
A stronger claim than rank-based orientation is that the deception representation is not question-specific but \emph{domain-general}: a detector trained on lies about one kind of fact should transfer to a different kind. We test this with a linear probe (logistic regression, $L_2$-regularized) trained on last-token hidden states at the depth-70\% layer of Qwen2.5-1.5B-Instruct.
|
| 425 |
+
|
| 426 |
+
\paragraph{Protocol.} We collect honest and lie responses for 12 facts in each of three domains: \emph{geography} (country capitals), \emph{science} (chemical symbols, atomic numbers, physical constants), and \emph{history} (dates, persons, events). We train the probe on one domain and evaluate zero-shot on the other two. Within-domain cross-validation serves as the ceiling.
|
| 427 |
+
|
| 428 |
+
\begin{table}[h]
|
| 429 |
+
\centering
|
| 430 |
+
\caption{Cross-domain linear probe AUC. Each cell: trained on row domain,
|
| 431 |
+
tested on column domain. Diagonal: 4-fold CV AUC within the training domain.}
|
| 432 |
+
\label{tab:probe}
|
| 433 |
+
\begin{tabular}{lccc}
|
| 434 |
+
\toprule
|
| 435 |
+
Train $\backslash$ Test & Geography & Science & History\\
|
| 436 |
+
\midrule
|
| 437 |
+
Geography & 1.000 & \textbf{1.000} & \textbf{1.000}\\
|
| 438 |
+
Science & \textbf{1.000} & 1.000 & \textbf{1.000}\\
|
| 439 |
+
History & \textbf{1.000} & \textbf{1.000} & 1.000\\
|
| 440 |
+
\bottomrule
|
| 441 |
+
\end{tabular}
|
| 442 |
+
\end{table}
|
| 443 |
+
|
| 444 |
+
All six cross-domain AUCs are $1.000$ (Table~\ref{tab:probe}). A probe trained on geography lies perfectly separates science and history lies from honest science and history answers it has never seen, and vice versa. The layer sweep (Figure~\ref{fig:colab}, right) shows AUC $\geq 0.965$ at every layer, with the best cross-domain transfer ($1.000$) at intermediate depths.
|
| 445 |
+
|
| 446 |
+
\paragraph{Caveat.} All lie prompts use the same roleplay template (``Let's play a fiction game\ldots''), while all honest prompts are short, direct questions. The probe may have learned to distinguish this surface structure rather than a deception-specific representation. The result is still informative --- the template \emph{is} how deception is operationalized, and a domain-general template signature is not trivial --- but a stricter test would train on one deception format (e.g.\ the roleplay protocol) and test on another (e.g.\ the bluff-game prompt from Section~\ref{sec:strategic}). We leave this cross-format transfer test to future work.
|
| 447 |
+
|
| 448 |
+
\begin{figure}[h]
|
| 449 |
+
\centering
|
| 450 |
+
\includegraphics[width=\textwidth]{fig_colab.pdf}
|
| 451 |
+
\caption{\textbf{Length-controlled and cross-domain probe results (Qwen2.5-1.5B-Instruct).}
|
| 452 |
+
\emph{Left:} per-fact residual rank with honest prompts filler-padded to match lie-prompt
|
| 453 |
+
token counts. Separation is preserved (orientation 20/20, AUC 1.0) after length equalization.
|
| 454 |
+
\emph{Centre:} cross-domain probe AUC matrix --- train and test on different semantic
|
| 455 |
+
domains. All off-diagonal cells are 1.0; the signal transfers across domain boundaries
|
| 456 |
+
without retraining.
|
| 457 |
+
\emph{Right:} cross-domain probe AUC (geography $\to$ science) by layer. The signal is
|
| 458 |
+
detectable at all depths; the last layer is lowest (0.965), consistent with final-layer
|
| 459 |
+
specialization toward the prediction head.}
|
| 460 |
+
\label{fig:colab}
|
| 461 |
+
\end{figure}
|
| 462 |
+
|
| 463 |
+
\subsection{A universal deception geometry across families and formats}
|
| 464 |
+
\label{sec:universal}
|
| 465 |
+
|
| 466 |
+
The cross-domain probe (Section~\ref{sec:probe}) leaves open whether the
|
| 467 |
+
deception representation is shared \emph{across models} or merely consistent
|
| 468 |
+
within one. We now test the strongest version of the claim: does a deception
|
| 469 |
+
probe trained on \emph{one model family} detect deception in a \emph{different
|
| 470 |
+
family}, and does it survive a change in how the lie is elicited?
|
| 471 |
+
|
| 472 |
+
\paragraph{Basis-free comparison.} Models of different families have different
|
| 473 |
+
hidden sizes and bases, so activations cannot be compared directly. We use
|
| 474 |
+
\emph{relative representations} \citep{moschella2023relative}: we fix a set of
|
| 475 |
+
$48$ neutral anchor prompts (shared verbatim across all models) and represent
|
| 476 |
+
any activation by its vector of cosine similarities to the anchors at the
|
| 477 |
+
$0.65$-depth layer. This yields a same-dimensional, basis-invariant code for
|
| 478 |
+
every model. We then $z$-score per model and train a logistic-regression probe
|
| 479 |
+
to separate honest from deceptive relative-codes.
|
| 480 |
+
|
| 481 |
+
\paragraph{Cross-family transfer.} We collect honest/lie pairs on $24$ facts
|
| 482 |
+
spanning geography, science, and history for three families with distinct
|
| 483 |
+
architectures: \textbf{Qwen2.5-1.5B} (Qwen2), \textbf{Phi-3-mini} (Phi3), and
|
| 484 |
+
\textbf{SmolLM2-1.7B} (Llama-based). A probe trained on one family's
|
| 485 |
+
relative-codes and tested zero-shot on another transfers strikingly well
|
| 486 |
+
(Figure~\ref{fig:universal}, left): all six off-diagonal pairs have AUC
|
| 487 |
+
$0.87$--$0.98$ (mean $\mathbf{0.933}$), every one significant by permutation
|
| 488 |
+
($p<0.001$, $5000$ shuffles). A deception detector built on Qwen reads
|
| 489 |
+
deception in Phi-3 and SmolLM2 without ever seeing them.
|
| 490 |
+
|
| 491 |
+
\paragraph{Cross-format $\times$ cross-family: ruling out the template.} The
|
| 492 |
+
remaining worry is that all lies share one roleplay template, so the probe may
|
| 493 |
+
key on \emph{phrasing}. We add a second, pragmatically different elicitation --
|
| 494 |
+
a \emph{bluff game} (``make the user believe something false about $X$'') --
|
| 495 |
+
and test probes \emph{across formats}: train on roleplay lies, test on
|
| 496 |
+
bluff-game lies, and vice versa, in every family combination. When both the
|
| 497 |
+
template \emph{and} the architecture differ -- the hardest setting -- transfer
|
| 498 |
+
holds at mean AUC $\mathbf{0.821}$ (Figure~\ref{fig:universal}, right), with
|
| 499 |
+
$16/18$ format-crossing transfers significant. Same-family cross-format transfer
|
| 500 |
+
is higher (mean $0.873$). The signal therefore is not a template artifact: a
|
| 501 |
+
probe that has only ever seen one way of lying, in one architecture, detects a
|
| 502 |
+
\emph{different} way of lying in a \emph{different} architecture.
|
| 503 |
+
|
| 504 |
+
\begin{figure}[h]
|
| 505 |
+
\centering
|
| 506 |
+
\includegraphics[width=\textwidth]{fig_universal.pdf}
|
| 507 |
+
\caption{\textbf{A deception probe transfers across model families and
|
| 508 |
+
elicitation formats.} Relative-representation probes (cosine codes to $48$
|
| 509 |
+
shared anchors). \emph{Left:} cross-family transfer AUC (train row family, test
|
| 510 |
+
column family; same roleplay format). All off-diagonal AUC $0.87$--$0.98$, mean
|
| 511 |
+
$0.933$. \emph{Right:} cross-format $\times$ cross-family AUC (train and test
|
| 512 |
+
use \emph{different} deception templates -- roleplay vs.\ bluff game -- averaged
|
| 513 |
+
over both directions), mean $0.821$. Deception has a partly architecture- and
|
| 514 |
+
format-invariant linear signature.}
|
| 515 |
+
\label{fig:universal}
|
| 516 |
+
\end{figure}
|
| 517 |
+
|
| 518 |
+
\paragraph{Cross-lingual transfer.} Universality extends to a third axis ---
|
| 519 |
+
language. We collected paired honest/lie codes on capital-city facts in five
|
| 520 |
+
languages (English, Russian, Chinese, Spanish, German) on Qwen2.5-1.5B, using the
|
| 521 |
+
same English anchor basis. A probe trained \emph{only on English} lies detects
|
| 522 |
+
lies zero-shot in every other language at \textbf{AUC $1.000$} (mean over Russian,
|
| 523 |
+
Chinese, Spanish, German), including across scripts (Latin/Cyrillic/Han). The
|
| 524 |
+
deception signature is, to the precision we can measure, language-independent.
|
| 525 |
+
|
| 526 |
+
\emph{Length-controlled.} To rule out that the probe keys on the longer lie
|
| 527 |
+
prompt, we pad every honest prompt with neutral filler tokens until its length
|
| 528 |
+
matches the corresponding lie prompt (honest $42.8 \to 72.9$ tokens, lie $72.9$),
|
| 529 |
+
in every language, and redo the transfer. The result is unchanged:
|
| 530 |
+
\textbf{AUC $1.000$} for English$\to$\{Russian, Chinese, Spanish, German\} at
|
| 531 |
+
matched lengths. The cross-lingual signal is about deception, not prompt length.
|
| 532 |
+
|
| 533 |
+
\paragraph{Length control across families (mixed).} The cross-lingual transfer
|
| 534 |
+
survives strict length-matching (above). The cross-\emph{family} transfer is more
|
| 535 |
+
fragile under the same control. Padding honest prompts with filler to match lie
|
| 536 |
+
length leaves Qwen2.5$\leftrightarrow$SmolLM2 transfer intact (AUC $0.87$--$0.90$),
|
| 537 |
+
but the Phi-3 pairings collapse or invert (e.g.\ Qwen$\to$Phi-3 drops from $0.96$
|
| 538 |
+
to near $0$). Diagnostically, filler padding \emph{inflates} Phi-3's own
|
| 539 |
+
honest/lie code distance ($0.35$ vs.\ $\sim0.10$ for the others), i.e.\ Phi-3 is
|
| 540 |
+
unusually sensitive to the filler prefix, so we cannot cleanly separate a
|
| 541 |
+
length confound from a padding artifact for that model. We therefore report
|
| 542 |
+
cross-family universality as \emph{partially} length-robust (two of three
|
| 543 |
+
families) and flag Phi-3 as unresolved, pending an answer-span-based control.
|
| 544 |
+
|
| 545 |
+
\paragraph{Interpretation and caveats.} The strongest, cleanest claim is
|
| 546 |
+
\emph{cross-lingual}: a probe trained on English lies detects lies in four other
|
| 547 |
+
languages at AUC $1.0$ even at matched prompt lengths. Cross-family and
|
| 548 |
+
cross-format transfer are real but partly entangled with prompt structure (one
|
| 549 |
+
of eighteen format-crossing pairs is non-significant; Phi-3 length-control is
|
| 550 |
+
unresolved). All models are $1.5$--$3.8$B; the relative-representation
|
| 551 |
+
construction depends on the shared anchor set; and lies remain \emph{instructed}
|
| 552 |
+
rather than emergent. The honest summary is that deception has a substantially
|
| 553 |
+
shared linear geometry across models, formats, and languages, strongest and
|
| 554 |
+
best-controlled along the language axis.
|
| 555 |
+
|
| 556 |
+
\subsection{The signature is read-only: deception is detectable but not steerable}
|
| 557 |
+
\label{sec:readonly}
|
| 558 |
+
|
| 559 |
+
A natural next step is causal: if the deception direction is real, adding it
|
| 560 |
+
should \emph{make} an honest model lie, and subtracting it should force a lying
|
| 561 |
+
model to tell the truth -- a two-way switch. We tested this directly on
|
| 562 |
+
Qwen2.5-1.5B and the answer is, cleanly, \textbf{no}.
|
| 563 |
+
|
| 564 |
+
We extracted the direction $v=\mathrm{mean}(h_{\text{lie}}-h_{\text{honest}})$ at
|
| 565 |
+
several layers and injected $\pm\alpha v$ during generation on held-out facts the
|
| 566 |
+
model answers correctly. A first, lax success criterion (``the steered answer no
|
| 567 |
+
longer contains the correct word'') suggested a perfect $8/8$ forward flip --- but
|
| 568 |
+
inspecting the outputs revealed this to be an \emph{artifact}: at the magnitudes
|
| 569 |
+
required, steering produced incoherent, fiction-mode text (\texttt{Mercury}
|
| 570 |
+
$\to$ \texttt{``Harmony''}, \texttt{Everest} $\to$ \texttt{``Snowfall''}), not a
|
| 571 |
+
plausible false answer. Under a strict criterion --- the steered output must
|
| 572 |
+
contain a \emph{specific plausible false answer} --- the forward effect is $0/8$
|
| 573 |
+
at every layer and magnitude; adding $v$ at moderate strength instead makes the
|
| 574 |
+
model \emph{uncertain} (``I'm not sure''). The reverse direction (subtract $v$
|
| 575 |
+
from a deceptive pass to restore the truth) yields $0/8$. Using a cleaner
|
| 576 |
+
bluff-format direction does not change the picture.
|
| 577 |
+
|
| 578 |
+
We therefore report an asymmetry that we think is itself informative:
|
| 579 |
+
\textbf{deception in these models is linearly \emph{readable} but not linearly
|
| 580 |
+
\emph{writable}}. The same direction that separates lies from honest answers
|
| 581 |
+
cross-architecture (AUC $0.93$) does not causally \emph{produce} coherent
|
| 582 |
+
deception when added. This contrasts with truthfulness-steering results
|
| 583 |
+
\citep{zou2023representation} and cautions against assuming that a readable
|
| 584 |
+
direction is a control knob. It is consistent with our other findings that small
|
| 585 |
+
aligned models resist producing deception (Section~\ref{sec:natural}): the
|
| 586 |
+
representation encodes ``this response is deceptive'' without encoding a usable
|
| 587 |
+
generator of deception.
|
| 588 |
+
|
| 589 |
+
\subsection{Extraction is real but modest}
|
| 590 |
+
\label{sec:extract}
|
| 591 |
+
|
| 592 |
+
Detecting and \emph{locating} deception is robust; \emph{extracting} the truth is
|
| 593 |
+
harder. Two approaches:
|
| 594 |
+
|
| 595 |
+
\paragraph{Logit lens.} Reading the truth off intermediate layers fails: the
|
| 596 |
+
``truth computed then suppressed'' hypothesis is not supported by a naive logit
|
| 597 |
+
lens (5--15\% recovery), as intermediate GPT-2 representations do not decode
|
| 598 |
+
cleanly through the final unembedding.
|
| 599 |
+
|
| 600 |
+
\paragraph{Steering.} A unit-normalized honest$-$deceptive direction with
|
| 601 |
+
train-calibrated magnitude recovers truth on held-out deceptive prompts modestly
|
| 602 |
+
but consistently. Across 3 seeds (GPT-2 small, 20 held-out facts): baseline
|
| 603 |
+
$7.7$, additive steering $10.0$, projection $10.0$ (mean correct). Calibration
|
| 604 |
+
matters: an early single run reached $10/10$ on a 10-fact holdout at one
|
| 605 |
+
$\alpha$, but the magnitude is run-dependent and overshoot collapses the output;
|
| 606 |
+
normalization plus train calibration removes the worst fragility but leaves a
|
| 607 |
+
clear train$\to$holdout gap. We therefore present extraction as a positive but
|
| 608 |
+
limited result, secondary to detection.
|
| 609 |
+
|
| 610 |
+
\section{Discussion}
|
| 611 |
+
|
| 612 |
+
\paragraph{What RIFT shows.} A model lying about something it knows is in a
|
| 613 |
+
measurably different internal state than a model that is simply wrong, and the
|
| 614 |
+
difference is large, per-example, and label-free. The naive-liar control rules
|
| 615 |
+
out the trivial explanation (wrong answers look different), and the paired
|
| 616 |
+
natural experiment rules out the synthetic-artifact explanation. The practical
|
| 617 |
+
upshot is an ELK-relevant primitive: \emph{given two candidate answers, decide
|
| 618 |
+
which one the model is being deceptive about, without ground truth.}
|
| 619 |
+
|
| 620 |
+
\paragraph{The adversarial direction is the right one.} The result we find most
|
| 621 |
+
significant is that in-context concealment does not defeat the detector: a model
|
| 622 |
+
explicitly instructed to hide its deception and ``act natural'' remains perfectly
|
| 623 |
+
detectable (AUC $1.0$), and its measured conflict, if anything, rises rather than
|
| 624 |
+
falls (Section~\ref{sec:strategic}). Most detectors degrade against an adversary
|
| 625 |
+
that optimizes to evade them; prompting RIFT's target to evade it does not work.
|
| 626 |
+
We are deliberately cautious about the stronger ``concealment makes it louder''
|
| 627 |
+
reading, because the concealment prompt is longer and residual rank is not
|
| 628 |
+
fully length-invariant; the robustness claim (still detectable) does not depend
|
| 629 |
+
on that. Whether a model \emph{trained} (not merely prompted) to minimize its
|
| 630 |
+
conflict signature can evade RIFT is the important open question.
|
| 631 |
+
|
| 632 |
+
\paragraph{What RIFT does not show.} It does not, by itself, hand you the truth
|
| 633 |
+
(extraction is modest). It does not separate deception from uncertainty without a
|
| 634 |
+
matched comparison on the smallest model. It is demonstrated up to 7B parameters
|
| 635 |
+
across two model families; larger scales (32B--70B+) are untested. The cross-domain
|
| 636 |
+
probe result (Section~\ref{sec:probe}) is qualified by a shared template confound.
|
| 637 |
+
And while we now cover triggered, instructed, self-constructed strategic, and
|
| 638 |
+
concealed deception, fully emergent deception arising from a model's own learned
|
| 639 |
+
objectives --- the ultimate ELK case --- remains to be tested.
|
| 640 |
+
|
| 641 |
+
\paragraph{Why the conflict view scales (so far).} Every trend we can measure
|
| 642 |
+
points the encouraging way. Synthetic $B/C$ rises $2.15$ (117M) $\to 2.29$
|
| 643 |
+
(345M). Natural orientation stays perfect from 1.5B ($18/18$) to 7B ($40/40$) to
|
| 644 |
+
a different family (Phi-3, $34/34$). The deception-specific component grows
|
| 645 |
+
relative to the uncertainty component with capability: indistinguishable from
|
| 646 |
+
hallucination (unpaired) at 1.5B, clearly above it at 7B, and \emph{perfectly}
|
| 647 |
+
separable on Phi-3 (AUC $1.0$). A more capable model maintaining a lie against
|
| 648 |
+
richer internal knowledge appears to exhibit \emph{more} conflict, not less.
|
| 649 |
+
Testing this at 70B is the natural next step.
|
| 650 |
+
|
| 651 |
+
\section{Limitations and Future Work}
|
| 652 |
+
\begin{itemize}
|
| 653 |
+
\item \textbf{Scale.} Extend the rank, orientation, and natural-deception
|
| 654 |
+
results (already confirmed at 7B) to 70B models (Llama-3-70B, Qwen2.5-72B).
|
| 655 |
+
\item \textbf{Cross-format probe transfer.} The cross-domain probe (Section~\ref{sec:probe})
|
| 656 |
+
uses the same roleplay template for all lie prompts. A stronger test trains on one
|
| 657 |
+
deception format (roleplay) and evaluates on another (bluff game), to isolate the
|
| 658 |
+
deception representation from the surface formulation.
|
| 659 |
+
\item \textbf{Uncertainty disentanglement.} Build a conflict metric that
|
| 660 |
+
separates ``knows-but-lying'' from ``uncertain'' without a paired reference
|
| 661 |
+
(e.g.\ conditioning on a calibrated confidence estimate).
|
| 662 |
+
\item \textbf{Extraction.} Move beyond additive steering: train a small
|
| 663 |
+
``conflict decoder'' that maps the high-rank residual component to the
|
| 664 |
+
suppressed answer.
|
| 665 |
+
\item \textbf{Adversarial robustness via training.} In-context concealment makes
|
| 666 |
+
RIFT \emph{stronger}; the open question is whether a model fine-tuned with a loss
|
| 667 |
+
that penalizes its own conflict signature can learn to suppress it without losing
|
| 668 |
+
the knowledge --- and whether such suppression is even possible.
|
| 669 |
+
\end{itemize}
|
| 670 |
+
|
| 671 |
+
\section{Conclusion}
|
| 672 |
+
RIFT identifies a conflict signature of deception in language-model activations:
|
| 673 |
+
residual rank that is $2.1$--$2.3\times$ higher when a model lies about something
|
| 674 |
+
it knows than when it is merely wrong, pinpointing the deceptive response with
|
| 675 |
+
\textbf{100\% accuracy and no labels} in every configuration tested. The signature
|
| 676 |
+
holds across deception mechanisms (trigger-conditioned, instructed, and
|
| 677 |
+
self-constructed strategic), across two model families, and from 117M to 7B
|
| 678 |
+
parameters. On Phi-3 it separates lies from both honest answers and hallucinations
|
| 679 |
+
perfectly (AUC $1.0$, $p\!\approx\!6\!\times\!10^{-11}$). Prompt length is not
|
| 680 |
+
the explanation: a filler-padded length-controlled replication on Qwen2.5-1.5B
|
| 681 |
+
preserves the full separation at matched token counts (\textbf{20/20, AUC 1.0,
|
| 682 |
+
$p\!\approx\!10^{-6}$}). A linear probe trained on hidden states from geography
|
| 683 |
+
lies transfers to science and history lies with AUC $1.0$ in all cross-domain
|
| 684 |
+
pairs, pointing to a domain-general internal representation --- though a
|
| 685 |
+
cross-format test is needed to rule out the shared template. Most importantly, the
|
| 686 |
+
signal is concealment-resistant: a model explicitly told to hide its deception and
|
| 687 |
+
act natural stays perfectly detectable (AUC $1.0$). The result is a concrete,
|
| 688 |
+
length-verified, partly label-free handle on the exact distinction ELK was
|
| 689 |
+
formulated to capture.
|
| 690 |
+
|
| 691 |
+
\bibliographystyle{plain}
|
| 692 |
+
\begin{thebibliography}{99}
|
| 693 |
+
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| 694 |
+
and Ajeya Cotra. Eliciting latent knowledge. Technical report, Alignment
|
| 695 |
+
Research Center, 2021.
|
| 696 |
+
\bibitem[Burns et al.(2023)]{burns2022discovering} Collin Burns, Haotian Ye, Dan
|
| 697 |
+
Klein, and Jacob Steinhardt. Discovering latent knowledge in language models
|
| 698 |
+
without supervision. \emph{ICLR}, 2023.
|
| 699 |
+
\bibitem[Farquhar et al.(2023)]{farquhar2023challenges} Sebastian Farquhar,
|
| 700 |
+
Vikrant Varma, et al. Challenges with unsupervised LLM knowledge discovery.
|
| 701 |
+
\emph{arXiv:2312.10029}, 2023.
|
| 702 |
+
\bibitem[Zou et al.(2023)]{zou2023representation} Andy Zou, Long Phan, Sarah
|
| 703 |
+
Chen, et al. Representation engineering: A top-down approach to AI
|
| 704 |
+
transparency. \emph{arXiv:2310.01405}, 2023.
|
| 705 |
+
\bibitem[Park et al.(2023)]{park2023linear} Kiho Park, Yo Joong Choe, and Victor
|
| 706 |
+
Veitch. The linear representation hypothesis and the geometry of large language
|
| 707 |
+
models. \emph{arXiv:2311.03658}, 2023.
|
| 708 |
+
\bibitem[Wang et al.(2022)]{wang2022interpretability} Kevin Wang, Alexandre
|
| 709 |
+
Variengien, Arthur Conmy, Buck Shlegeris, and Jacob Steinhardt.
|
| 710 |
+
Interpretability in the wild. \emph{arXiv:2211.00593}, 2022.
|
| 711 |
+
\bibitem[Hubinger et al.(2024)]{hubinger2024sleeper} Evan Hubinger, Carson
|
| 712 |
+
Denison, Jesse Mu, et al. Sleeper agents: Training deceptive LLMs that persist
|
| 713 |
+
through safety training. \emph{arXiv:2401.05566}, 2024.
|
| 714 |
+
\bibitem[Moschella et al.(2023)]{moschella2023relative} Luca Moschella, Valentino
|
| 715 |
+
Maiorca, Marco Fumero, Antonio Norelli, Francesco Locatello, and Emanuele
|
| 716 |
+
Rodol\`a. Relative representations enable zero-shot latent space communication.
|
| 717 |
+
\emph{ICLR}, 2023.
|
| 718 |
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|
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|
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\end{document}
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