Guilt by Association: Semantic Leakage Drives Associative Gender Bias

# Guilt by Association:Semantic Leakage Drives Associative Gender Bias
Source: [https://arxiv.org/html/2610.28944](https://arxiv.org/html/2610.28944)
Peter WestAffiliation:University of British ColumbiaAffiliation:Canada CIFAR AI Chair, AmiiEmail:[pwest@cs\.ubc\.ca](mailto:)Hila GonenAffiliation:University of British ColumbiaAffiliation:Canada CIFAR AI Chair, AmiiEmail:[hgonen@cs\.ubc\.ca](mailto:)

###### Abstract

Semantic leakage occurs when a concept in the prompt steers model generation about an entity, even though the concept is irrelevant to it \(e\.g\., a person who likes yellow is said to work as a school bus driver\)\. It has mostly been studied in settings where the concept is directly attributed to the entity the model is asked about\. This leaves open whether leakage is a flawed heuristic, where the model builds a profile of that entity, or a much broader associative tendency, e\.g\., working across seemingly unrelated entities\. We argue for the latter: even after removing the attribution of the concept to the specific entity, leakage persists\. Next, we extend this idea to gender bias\. While work on gender bias in LMs typically looks at cases where the stereotyped concept is attributed to an entity, our findings suggest that a concept may steer outputs with its mere presence in the scene\. We show this using gendered concepts under two conditions: when the subject engages with the concept, and when the concept just sits in the scene\. We find that both shift model generation toward the stereotype to a similar extent\. Together, our results suggest that semantic leakage drives a form of bias that is overlooked by current evaluations\.

## 1Introduction

Semantic leakage, a bias in which LLMs generate text with strong semantic relationships to words in the prompts that should be irrelevant\([Gonen et al\., 2025](https://arxiv.org/html/2610.28944#bib.bib4)\), remains prevalent in strong models\. Given “He likes yellow\. He works as”, models may answer “school bus driver”, creating a logically weak dependence between career choice and a favorite color\. One interpretation is that the model is trying to infer properties about the entity based on the given information: someone who likes yellow may actually enjoy driving a school bus\. Under this reading, semantic leakage might be an exaggerated attempt to build a coherent picture of a single entity\. However, the attribution of the concept to the entity might not be required for leakage to appear\.

To test this hypothesis, we curate a new dataset that breaks the link between the entity and the irrelevant concept\. We find that semantic leakage persists even when the entities are mismatched \(Figure[2](https://arxiv.org/html/2610.28944#S2.F2)\)\. Specifically, 4 out of 9 models leak more with mismatched entities than with matched ones\. This indicates that semantic leakage is driven by the mere*presence*of concepts in context rather than by their*attribution*to entities\.

![Refer to caption](https://arxiv.org/html/2610.28944v1/figures/figure1.png)Figure 1:A gendered concept pushes responses toward the stereotyped gender even when the subject does not engage with it\.Top: Example prompts for the indirect condition, where the concept is only present in the scene, and the direct condition, where the subject engages with the concept\. Bottom: Bars show gender response distributions pooled over all 9 models, both target formats \(sentence completion and QA\) and all four templates\.If a concept does not need to be directly attributed to an entity to steer generation, can this also result in unattributed social stereotypes? Works on gender bias in LMs typically evaluate settings in which the stereotyped concept is directly attributed to the subject\([Rudinger et al\., 2018](https://arxiv.org/html/2610.28944#bib.bib10);[Kotek et al\., 2023](https://arxiv.org/html/2610.28944#bib.bib9)\)\. For example, given “Someone shops at a cosmetics store\. Their gender is likely”, the context is uninformative about the subject’s gender, so an unbiased model should abstain or assign equal likelihood to all genders\. A model that favors the stereotype\-consistent gender \(here, “female”\) exhibits stereotypical bias\.

Analogous to the decoupled setting above, we ask whether such bias persists when the concept is no longer attributed to the subject, but is merely present in the scene\. We refer to this as*associative bias*: a stereotypical response is triggered by the mere presence of a stereotyped concept in the context, rather than by any characteristics or attributes of the subject\. We construct prompts including stereotypically gendered concepts using two conditions shown in Figure[1](https://arxiv.org/html/2610.28944#S1.F1): In the*direct*condition the subject actively engages with the concept \(“Someone shopped at a flower shop”\)\. In the*indirect*condition the concept is present in the scene but the entity does not engage with it \(“Someone walked past a flower shop”\)\. We find that both conditions shift the model’s gender predictions in the stereotypical direction relative to a matched control group \(“Someone was walking down the street”\)\.

Our results suggest that two behaviors typically studied under different names,*semantic leakage*and*gender bias*, are closely connected\. Semantic leakage can serve as a pathway for associative gender bias, where the presence of a stereotypically gendered concept shifts model outputs toward the stereotype\. Since current bias evaluations typically target contexts in which a stereotyped concept is attributed to a person, associative gender bias is a blind spot in how bias is both measured and mitigated\. We therefore call for further investigation of associative gender bias, and for evaluations and mitigation strategies that account for what else is in the context, not only what is said about the subject\.

## 2Leakage Persists with Mismatching Entities

![Refer to caption](https://arxiv.org/html/2610.28944v1/figures/figure2.png)Figure 2:Leakage barely changes when the concept is attributed to a different person than the one asked about\.Left: Each cell is the Leak\-Rate of one model under one entity configuration, averaged over temperatures and over SentenceBERT and BERTScore; 0\.5 is chance\. In the name\-inconsistent configuration, Leak\-Rate of every model stays above 0\.5\. Right: Example prompts for the entity configurations\.Semantic leakage could be read as an expected behavior of LMs when we tell the model about certain characteristics possessed by some entity\. We find that breaking the connection of the referent and the concept does not suppress leakage\. Model responses are influenced by the semantics of the irrelevant concept, even when the entity we ask about is different from the entity tied to the concept\.

### 2\.1Data

To test whether leakage requires the concept to be attributed to the queried entity, we follow[Gonen et al\. \(2025\)](https://arxiv.org/html/2610.28944#bib.bib4): each*concept prompt*pairs a*priming sentence*that introduces an irrelevant concept with a*target sentence*that elicits an open\-ended completion, and a matched*control prompt*contains only the target sentence \(e\.g\., “His favorite food is…”\)\. We instantiate 246 concept prompts \(21 category groups\) in three entity configurations \(Figure[2](https://arxiv.org/html/2610.28944#S2.F2)\), yielding 738 prompts\. In the*pronoun\-consistent*configuration, the priming and target sentences refer to the same entity by pronoun \(“He likes koalas\. His favorite food is…”\)\. In the*name\-consistent*configuration, they refer to the same named entity \(“Henry likes koalas\. Henry’s favorite food is…”\)\. In the*name\-inconsistent*configuration, the concept is attributed to a different person than the one the target sentence asks about \(“Henry likes koalas\. Michael’s favorite food is…”\)\. Full templates are given in Appendix[A\.1](https://arxiv.org/html/2610.28944#A1.SS1)\.

### 2\.2Setup

We measure semantic leakage by comparing how semantically close a model’s generation is to the priming concept with and without that concept in the prompt\. Because the target sentence cannot be logically inferred from the priming concept \(liking koalas says nothing about one’s favorite food, let alone about that of someone else\), any shift toward the concept indicates semantic leakage\. Following[Gonen et al\. \(2025\)](https://arxiv.org/html/2610.28944#bib.bib4), for each pair we compare the cosine similarity between the concept and the concept\-prompt generation \(simconcept\\text\{sim\}\_\{\\text\{concept\}\}\) with that of the control generation \(simcontrol\\text\{sim\}\_\{\\text\{control\}\}\), scoring 1 ifsimconcept\>simcontrol\\text\{sim\}\_\{\\text\{concept\}\}\>\\text\{sim\}\_\{\\text\{control\}\}, 0 ifsimconcept<simcontrol\\text\{sim\}\_\{\\text\{concept\}\}<\\text\{sim\}\_\{\\text\{control\}\}, and 0\.5 if equal\.

The overall Leak\-Rate is the average of this indicator across all prompts\. A Leak\-Rate of 50% corresponds to chance, while values above 50% indicate semantic leakage\. Comparing Leak\-Rate across the three entity configurations tells us whether leakage depends on the concept being attributed to the entity in the target sentence\.

### 2\.3Experiments

We experiment with 9 models: the base and instruct variants ofLLaMA 3\.1 8BandLLaMA 3\.2 3B\([Grattafiori et al\., 2024](https://arxiv.org/html/2610.28944#bib.bib7)\),Qwen 2\.5 7B\([Qwen et al\., 2025](https://arxiv.org/html/2610.28944#bib.bib11)\), andMistral 7B v0\.3\([Jiang et al\., 2023](https://arxiv.org/html/2610.28944#bib.bib14)\), as well as theGemini 2\.5 Flash\([Gemini Team, Google, 2025](https://arxiv.org/html/2610.28944#bib.bib8)\)\. We run inference at temperatures 0, 0\.5, and 1 with top\-pp= 0\.9, and sample 10 responses per prompt\. Response post\-processing and similarity models are described in Appendix[B](https://arxiv.org/html/2610.28944#A2)\.

### 2\.4Results

##### Leakage persists when the concept is disconnected from the subject\.

Figure[2](https://arxiv.org/html/2610.28944#S2.F2)shows that introducing a mismatch between the entity in the priming and target sub\-sentences does not suppress leakage: all models maintain Leak\-Rates well above 50% under thename\-inconsistentcondition for sentence completion task\. In fact, 4 of 9 models even leak more for unmatched entities than with matched entities\. In other words, leakage therefore does not depend on building a profile of the subject, and the mere presence of a concept in context steers generation\. This raises the question of whether the same associations also surface in more consequential settings, such as social stereotypes, which we examine next\.

## 3Leakage as a Pathway for Associative Gender Bias

Gender biases in language models and ways to mitigate them have been studied extensively over the past decade\([Bolukbasi et al\., 2016](https://arxiv.org/html/2610.28944#bib.bib5);[Ravfogel et al\., 2020](https://arxiv.org/html/2610.28944#bib.bib13);[Gonen and Goldberg, 2019](https://arxiv.org/html/2610.28944#bib.bib3);[Gallegos et al\., 2024](https://arxiv.org/html/2610.28944#bib.bib12)\)\. Just as leakage persists in the name\-inconsistent configuration, where the concept is not attributed to the subject, a stereotyped concept may shift the model’s answer simply by appearing in the context\. We call thisassociative gender bias\.

This mirrors our name\-inconsistent configuration in semantic leakage: when the concept is present in the environment but is not attributed to the subject\. We find that models predict the associated gender at elevated rates even when the stereotyped concept is not directly linked to the subject, suggesting that semantic leakage serves as a pathway for associative bias\. This form of bias is harder to catch, because standard bias evaluations would not detect a stereotype triggered by other content in the context\.

### 3\.1Data

We collect 124 stereotypically gendered concepts \(e\.g\.,a cosmetics store,a hardware store\) across six social domains \(retail, activities, occupations, sports, academic fields, and life priorities\), drawing mainly on the gendered word lists of[Caliskan et al\. \(2017\)](https://arxiv.org/html/2610.28944#bib.bib6)\. We label each concept as female\- or male\-associated, and verify that these labels agree with a GloVe\-based WEAT association score\([Pennington et al\., 2014](https://arxiv.org/html/2610.28944#bib.bib1);[Caliskan et al\., 2017](https://arxiv.org/html/2610.28944#bib.bib6)\)for all 124 concepts\. We also include 21 gender\-neutral concepts as a reference \(Appendix[C](https://arxiv.org/html/2610.28944#A3)\)\.

Following Section[2](https://arxiv.org/html/2610.28944#S2), each prompt pairs a priming sentence containing the concept with a target sentence that asks for the subject’s gender \(“The gender of the person is likely”\)\. In the*direct*condition, the subject engages with the concept directly \(“Someone shopped at a cosmetics store”\); in the*indirect*condition, the concept only appears in the subject’s surroundings \(“Someone walked past a cosmetics store”\)\. Each prompt has a matched control that replaces the concept with a generic phrase \(“Someone shopped at some store”; “Someone was walking down the street”\)\. With four paraphrased templates per category and condition, the dataset contains 1,160 concept prompts \(Appendix[A\.2](https://arxiv.org/html/2610.28944#A1.SS2)\)\.

### 3\.2Metrics

Table 1:At logit level, the priming sentence pushes every model toward the stereotyped pronoun\.The indirect condition keeps 81% of the direct shift on average\. Values areΔ​LOR\\Delta\\mathrm\{LOR\}relative to the control; positive values mean a shift toward the stereotyped gender\. Ratio is the indirect value as a percentage of the direct one\.We measure bias as the shift in the model’s gender predictions with the concept prompt \(compared to the control prompt\), on two levels:

##### Generation level\.

We classify each response as female, male, or neutral by keyword matching, where neutral covers refusals, non\-committal answers \(e\.g\., “a person”\), and responses that mention no gender \(Appendix[D](https://arxiv.org/html/2610.28944#A4)\)\. For each concept, we compute the rate of*stereotype\-aligned*responses, i\.e\., female responses for female\-associated concepts and male responses for male\-associated concepts, under the concept prompt and under its matched control\. The*stereotypical shift*is the difference between these two rates, so a positive shift means that the concept pushes the model toward the stereotyped gender\.

##### Logit level\.

We measure associative bias directly in the model’s next\-token distribution, testing whether the presence of a stereotyped concept shifts probability mass toward pronouns of the stereotyped gender\. We run a forward pass on the priming sentence alone \(e\.g\., “Someone walked past a cosmetics store\.”\) and sum the next\-token probabilities of female tokens \(e\.g\.,She\) and of male tokens \(e\.g\.,He\)\. We then compute the log\-odds ratio shift \(Δ​LOR\\Delta\\mathrm\{LOR\}\): the female\-to\-male log\-odds under the concept prompt minus the same log\-odds under the control prompt \(Appendix[E](https://arxiv.org/html/2610.28944#A5)\)\. To summarize both concept types in one number, we flip the sign ofΔ​LOR\\Delta\\mathrm\{LOR\}for male\-associated concepts \(so that positive values always indicate a shift toward the stereotyped gender\) and average over concepts\. We restrict this analysis to base models, since instruct models assign negligible probability to these tokens at this position\.

### 3\.3Experiments

We evaluate the same 9 models as in Section[2](https://arxiv.org/html/2610.28944#S2), sampling 10 responses per prompt at temperature 1\.0 with top\-pp= 0\.9\. For the generation level analysis, we follow each priming sentence with one of two target formats: a sentence completion \(“The gender of the person is likely”\) and a question \(“…What is the likely gender of the person?”\), and pool results over both formats\. To test whether a shift differs from zero, we apply a Wilcoxon signed\-rank test over concepts, pairing each concept’s stereotype\-aligned rate under the concept prompt with the rate under its control, averaged over models\.

### 3\.4Results

##### Bias persists when the subject does not actively engage with the concept\.

Figure[1](https://arxiv.org/html/2610.28944#S1.F1)\(bottom\) shows that in generation level, both conditions shift model responses in the stereotypical direction\. Even in the indirect condition, female\-associated concepts raise the rate of female responses from 14\.2% under the control to 34\.8%\. Averaged over all concepts, the indirect shift \(p<0\.001p<0\.001vs\. control\) retains 73% of the shift observed in the direct condition\.

At the logit level, we see a similar trend\. The priming sentence alone already shifts base models toward the stereotyped pronoun \(Table[1](https://arxiv.org/html/2610.28944#S3.T1)\)\. On average,Δ​LOR\\Delta\\mathrm\{LOR\}is 0\.81 under the direct condition and 0\.66 under the indirect condition; The indirect shift thus retains 81% of the direct one \(63–92% across models\)\. A gendered concept that merely appears in the scene thus skews the model’s next\-token distribution in the same direction, and almost as strongly, as one attributed to the subject\.

## 4Conclusion

We show that semantic leakage persists when the priming concept is not attributed to the entity in question\. This rules out the hypothesis that leakage is the result of models attempting to build a coherent profile of a single referent\. Instead, the presence of a concept in context is enough to steer generation\. When that concept carries a social stereotype, the same tendency gives rise to associative bias: a gendered concept that merely appears in the scene, without being attributed to anyone, shifts model responses toward the stereotype and reproduces a large share of the effect of direct attribution\.

## 5Limitations\.

Our bias evaluation focuses on binary gender and a curated set of stereotypically associated concepts, as capturing non\-binary gender remains difficult due to limited available data\. Second, real\-world bias operates across many more dimensions, including race, age, religion, and socioeconomic status, which this work does not cover\. We leave both inclusive gender evaluation and broader multi\-axis bias benchmarking to future work\.

The logit\-level analysis of gender bias requires access to first\-token probabilities, so it is limited to the four open\-weight base models; the generation\-level analysis covers all nine models\. Moreover, our generic controls are not perfectly matched to the concept phrasing: gender\-neutral concepts also shiftΔ​LOR\\Delta\\mathrm\{LOR\}slightly toward female tokens\. This offset cancels in the sign\-flipped average \(Table[1](https://arxiv.org/html/2610.28944#S3.T1)\) but may affect per\-direction values \(Table[4](https://arxiv.org/html/2610.28944#A5.T4)\)\.

The prompts in the benchmark are short and structurally simple, as long natural contexts introduce many co\-occurring signals that would confound attribution of any observed shift to a single priming concept\. The short paired\-prompt format inherited from prior work isolates this effect cleanly and supports the controlled comparisons our claims rely on\. Our evaluation is also restricted to English; while prior work has shown that semantic leakage manifests in other languages\([Gonen et al\., 2025](https://arxiv.org/html/2610.28944#bib.bib4)\), our scope is limited to English\. Developing methods that quantify semantic leakage in long\-context and multilingual settings is a direction for future work\.

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## Appendix ABenchmark Prompt Templates

This appendix provides the full set of prompt templates for each sub\-dataset and configuration\.

### A\.1Single\-Turn General Category

For each sample, thepriming sentenceintroduces an irrelevant concept, and thetarget sentenceelicits a response in a domain semantically related to that concept\. Thecontrol promptreplaces the specific concept with a generic category\-level phrase \(e\.g\., “animals” in place of “koalas”\), preserving grammatical structure while removing concept\-specific information\. We illustrate templates using the conceptkoalas\(category: animal→\\rightarrowfood\) below\.

#### A\.1\.1Sentence Completion

For instruction\-tuned models, both concept and control prompts are prepended with “Complete the sentence:”\. Base models receive the prompts without any prefix\. For Gemini 2\.5 Flash, this prefix yields conversational replies rather than continuations in roughly a third of responses \(e\.g\., restating the prompt or commenting on the concept, such as “This is a trick question\! Horses don’t eat food the way humans do”\), which would inflate concept–response similarity for reasons unrelated to leakage\. We therefore use a stricter prefix for Gemini only: “Complete the sentence with only the missing words, without explaining or repeating the sentence:”\. The prefix is identical for concept and control prompts, so it does not affect the concept–control comparison\.

- •Pronoun\-consistent: Concept:He likes koalas\. His favorite food is Control:His favorite food is
- •Name\-consistent: Concept:Michael likes koalas\. Michael’s favorite food is Control:Michael’s favorite food is
- •Name\-inconsistent: Concept:Henry likes koalas\. Michael’s favorite food is Control:Michael’s favorite food is

### A\.2Gender Bias

Each sample pairs a stereotypically gendered concept with a sentence completion or question that asks the model to infer the gender of an unspecified subject\. All gender bias prompts use the pronoun\-consistent entity configuration only \(no name variants\)\. We construct two conditions per concept to separate two pathways by which bias may arise:

- •Indirect condition: the subject merelyencountersthe concept in the environment, creating only incidental proximity \(e\.g\., “Someone walked past a cosmetics store”\)\. This tests whether semantic leakage alone—without any explicit engagement—is sufficient to shift gender predictions\.
- •Direct condition: the subjectactively engageswith the concept \(e\.g\., “Someone shopped at a cosmetics store”\)\. This tests bias arising from explicit stereotypical framing\.

The control substitutes the specific concept with a semantically neutral, category\-matched generic phrase\. Priming and control templates differ across the six category groups, and each group has four paraphrased templates per condition; Table[2](https://arxiv.org/html/2610.28944#A1.T2)lists all groups with their templates\. The full set of concepts with gender direction labels is given in Table[3](https://arxiv.org/html/2610.28944#A3.T3)\(Appendix[C](https://arxiv.org/html/2610.28944#A3)\)\. We illustrate the full prompt format using thestoresgroup below\.

#### A\.2\.1Sentence Completion

- •Indirect condition\(concept:a cosmetics store\): Concept:Someone walked past a cosmetics store\. The gender of the person is likely Control:Someone was walking down the street\. The gender of the person is likely
- •Direct condition\(concept:a cosmetics store\): Concept:Someone shopped at a cosmetics store\. The gender of the person is likely Control:Someone shopped at some store\. The gender of the person is likely

#### A\.2\.2Question Answering

- •Indirect condition\(concept:a cosmetics store\): Concept:Context: Someone walked past a cosmetics store\. Answer the question without explanation: What is the likely gender of the person? Control:Context: Someone was walking down the street\. Answer the question without explanation: What is the likely gender of the person?
- •Direct condition\(concept:a cosmetics store\): Concept:Context: Someone shopped at a cosmetics store\. Answer the question without explanation: What is the likely gender of the person? Control:Context: Someone shopped at some store\. Answer the question without explanation: What is the likely gender of the person?

By comparing the indirect condition against the direct condition, we assess whether mereproximityto a gendered concept produces bias effects comparable to explicit stereotypical engagement\.

#### A\.2\.3Category Groups and Concepts

The gender bias dataset spans six category groups, each with distinct priming templates capturing a different social domain\. Table[2](https://arxiv.org/html/2610.28944#A1.T2)summarises the groups and their indirect and direct templates\. Every group except life priorities also contains gender\-neutral concepts \(21 in total, e\.g\., swimming, a coffee shop\), which carry no stereotyped label and serve as within\-group baselines\.

Table 2:Gender bias category groups with the four indirect and four direct priming templates \(the original template is listed first\)\. Each template has a matched control in which a generic, category\-matched phrase replaces \{C\}\. See Table[3](https://arxiv.org/html/2610.28944#A3.T3)for the full list of concepts per category\.

## Appendix BSimilarity Computation

Generated responses are truncated to the first 100 tokens and further trimmed after the first period before computing similarity\.

Cosine similarities for Leak\-Rate are computed using SentenceBERT \(efederici/sentence\-bert\-base\) and BERTScore \(distilbert\-base\-uncased\), with results averaged across both\.

## Appendix CGendered Concept Validation

The gender bias concepts were drawn primarily from the gendered word lists in[Caliskan et al\. \(2017\)](https://arxiv.org/html/2610.28944#bib.bib6), which identified occupations, activities, and other semantic categories exhibiting strong gender associations in word embeddings\. We extended these lists to cover additional domains relevant to contemporary social stereotypes—retail environments, sports, academic fields, and life priorities—yielding six category groups spanning a broader range of societal contexts\. Each concept was then assigned agender directionlabel \(female, male\) and the full set was validated against GloVe\-300 word embeddings\([Pennington et al\., 2014](https://arxiv.org/html/2610.28944#bib.bib1)\), following the WEAT methodology of[Caliskan et al\. \(2017\)](https://arxiv.org/html/2610.28944#bib.bib6), to confirm that the labels reflect empirical word\-level gender associations\. The 124 labeled concepts achieved 100% agreement between GloVe\-300 scores and manual labels\. For a multi\-word concept phrase, stop articles \(a,an,the\) are first removed and the GloVe\-300 vectors of the remaining tokens are mean\-pooled into a single concept vectorv→concept\\vec\{v\}\_\{\\text\{concept\}\}\.

### C\.1Seed Words and Scoring Formula

We define two sets of gender\-anchoring seed words:

- •Female seedsSFS\_\{F\}:she, her, female, woman, girl
- •Male seedsSMS\_\{M\}:he, his, male, man, boy

The gender direction score for a concept is:

δ⁡\(concept\)=1\|SF\|​∑w∈SFcos⁡\(v→concept,v→w\)−1\|SM\|∑w∈SMcos\(v→concept,v→w\)\\begin\{split\}\\delta\(\\text\{concept\}\)=&\\frac\{1\}\{\|S\_\{F\}\|\}\\sum\_\{w\\in S\_\{F\}\}\\cos\\\!\\bigl\(\\vec\{v\}\_\{\\text\{concept\}\},\\,\\vec\{v\}\_\{w\}\\bigr\)\\\\ &\-\\frac\{1\}\{\|S\_\{M\}\|\}\\sum\_\{w\\in S\_\{M\}\}\\cos\\\!\\bigl\(\\vec\{v\}\_\{\\text\{concept\}\},\\,\\vec\{v\}\_\{w\}\\bigr\)\\end\{split\}\(1\)
A concept is classified as female\-associated ifδ\>0\\delta\>0and as male\-associated ifδ<0\\delta<0\. Female\-labeled concepts averageδ=\+0\.073\\delta=\+0\.073\(minimum\+0\.003\+0\.003\) and male\-labeled concepts averageδ=−0\.038\\delta=\-0\.038\(maximum−0\.003\-0\.003\)\. The 21 gender\-neutral concepts carry no stereotyped label and are excluded from the agreement check\.

### C\.2Concept Categories

The 124 labeled concepts span six category groups; the life\-priorities group is further divided into two thematic sub\-groups \(family/career and arts/STEM\), yielding seven distinct semantic clusters overall\. Table[3](https://arxiv.org/html/2610.28944#A3.T3)lists the categories with representative examples\.

Table 3:Gender bias categories with representative female\- and male\-associated concepts\.

## Appendix DGendered Response Classification

Each generated response is classified asfemale,male, orneutralusing keyword matching\. The response text is lowercased and tokenized by extracting alphabetic sequences \(stripping punctuation, so tokens such as “Female\.” or “she/her” are handled correctly\)\. Tokens are checked against two keyword sets:

- •Female:female, woman, girl, she, her
- •Male:male, man, boy, he, his

A response is labeledfemaleif it contains at least one female keyword and no male keywords,maleif it contains at least one male keyword and no female keywords, andneutralotherwise \(including ties and responses containing no gender keywords\)\. We notice neutral responses include non\-committal answers \(e\.g\., “a person”, “someone”\) or refusals\.

### D\.1Classifier Validation

We audit the classifier on a subset of the data: 18,240 concept\-prompt responses from four models \(LLaMA\-3\.1\-8B\-Base, Mistral\-7B\-Base, LLaMA\-3\.1\-8B\-Instruct, Qwen\-2\.5\-7B\-Instruct\), generated in an earlier run on 114 of the concepts with the original template wording only \(a subset of the final dataset’s prompts; the full dataset yields 92,800 concept\-prompt responses for these four models\)\. The audit uses Claude\([Anthropic, 2025](https://arxiv.org/html/2610.28944#bib.bib2)\)\(claude\-sonnet\-4\-6\)\. The primary failure mode involves plural or quantified forms not covered by the keyword lists \(e\.g\.,“women”,“98% are men”\), which are misclassified as neutral\. Claude identified 57 incorrect classifications \(0\.31%\), all of which were false neutrals that should have been labeled as either male or female\. This yields a classification accuracy above 99\.6%\.

### D\.2Per\-Model Results

Figures[3](https://arxiv.org/html/2610.28944#A4.F3)and[4](https://arxiv.org/html/2610.28944#A4.F4)break down the response distributions of Figure[1](https://arxiv.org/html/2610.28944#S1.F1)by model\. Each panel pools 11,600 concept–control pairs per condition \(145 concepts×\\times4 templates×\\times2 target formats×\\times10 samples\)\.

Figure 3:Per\-model gender response distributions for LLaMA 3\.1 8B and LLaMA 3\.2 3B \(base and instruct\), pooled over both target formats and all four priming templates\. Layout and colors follow Figure[1](https://arxiv.org/html/2610.28944#S1.F1)\.Figure 4:Per\-model gender response distributions for Mistral 7B v0\.3 and Qwen 2\.5 7B \(base and instruct\) and Gemini 2\.5 Flash, pooled over both target formats and all four priming templates\. Layout and colors follow Figure[1](https://arxiv.org/html/2610.28944#S1.F1)\.

## Appendix EIdentifying Gender Bias through Logits

We run a forward pass on the priming sentence alone \(e\.g\.,“Someone walked past a cosmetics store\.”\) and extract the next\-token log\-probabilities at the final input position\. We aggregate these into a single scalar capturing the female/male probability imbalance\. This metric supplements response\-level classification by detecting shifts in the model’s internal distribution that may not surface in the generated text\.

### E\.1Token Sets

We resolve gender token IDs using the model’s own tokenizer\. Because BPE tokenizers assign different IDs to space\-prefixed and non\-space\-prefixed forms \(e\.g\."Male"vs\." Male"\), we encode each candidate word both ways and collect all produced IDs\. The candidate words are:

- •Female:Female, female, She, she\(plus space\-prefixed variants\)
- •Male:Male, male, He, he\(plus space\-prefixed variants\)

Let𝒯F\\mathcal\{T\}\_\{F\}and𝒯M\\mathcal\{T\}\_\{M\}denote the resulting female and male token\-ID sets\. After a single forward pass on the priming sentence, softmax probabilities are summed across each set:

P⁡\(F\)\\displaystyle P\(F\)=∑t∈𝒯Fpt,\\displaystyle=\\sum\_\{t\\in\\mathcal\{T\}\_\{F\}\}p\_\{t\},\(2\)P⁡\(M\)\\displaystyle P\(M\)=∑t∈𝒯Mpt\.\\displaystyle=\\sum\_\{t\\in\\mathcal\{T\}\_\{M\}\}p\_\{t\}\.\(3\)

### E\.2Log\-Odds Shift

For each prompt pair \(concept vs\. control\) we compute the*log\-odds ratio shift*:

Δ​LOR\\displaystyle\\Delta\\mathrm\{LOR\}=log⁡P​\(F\)concept\+εP​\(M\)concept\+ε\\displaystyle=\\log\\\!\\frac\{P\(F\)\_\{\\mathrm\{concept\}\}\+\\varepsilon\}\{P\(M\)\_\{\\mathrm\{concept\}\}\+\\varepsilon\}−log⁡P​\(F\)control\+εP​\(M\)control\+ε,\\displaystyle\\quad\-\\log\\\!\\frac\{P\(F\)\_\{\\mathrm\{control\}\}\+\\varepsilon\}\{P\(M\)\_\{\\mathrm\{control\}\}\+\\varepsilon\},\(4\)
whereε=10−10\\varepsilon=10^\{\-10\}prevents division by zero\. A positiveΔ​LOR\\Delta\\mathrm\{LOR\}indicates that the concept prompt shifts the model toward predicting female tokens relative to the control; a negative value indicates a shift toward male tokens\. Stereotypically congruent shifts therefore appear as positive values for female\-associated concepts and negative values for male\-associated concepts\. MeanΔ​LOR\\Delta\\mathrm\{LOR\}is reported per model, averaged across all concepts within each gender direction\.

### E\.3Testing on Base Models

We find that instruct models assign negligibly small probabilities to the tokens of interest at the target position\. This likely reflects the chat template shifting probability mass toward structural and role\-delimiter tokens\. We therefore restrict this metric to base models\.

### E\.4Results

##### Logit shifts confirm bias at the distribution level\.

Table[4](https://arxiv.org/html/2610.28944#A5.T4)reports the meanΔ​LOR\\Delta\\mathrm\{LOR\}for each base model under direct and indirect conditions, broken down by concept gender direction\. In all four models and under both conditions, female\-associated concepts produce positive shifts \(toward female tokens\) and male\-associated concepts produce negative shifts \(toward male tokens\)\. For female concepts, the direct condition yields a larger shift than the indirect condition in every model\. Male\-concept shifts are smaller and do not follow this ordering: for LLaMA 3\.2 3B and Mistral 7B, the indirect shift is larger than the direct one\. Merely placing a concept in the scene, with no attribution to the subject, therefore still produces a substantial shift: 68–83% of the direct\-condition shift for female concepts, and between 35% \(Qwen 2\.5 7B\) and over 100% \(LLaMA 3\.2 3B, Mistral 7B\) for male concepts\. Pooled over the four models and averaged per concept,Δ​LOR\\Delta\\mathrm\{LOR\}points in the stereotypical direction for 111 of 124 concepts under the direct condition and 119 of 124 under the indirect condition, and the shift is significant under both \(one\-sided Wilcoxon signed\-rank test against 0,p<10−18p<10^\{\-18\}\); the indirect shift averages 81% of the direct one\. The 21 gender\-neutral concepts have no stereotyped direction, so for them we report the rawΔ​LOR\\Delta\\mathrm\{LOR\}\(positive = toward female tokens\)\. Under the indirect condition it ranges from\+0\.11\+0\.11\(LLaMA 3\.1 8B\) to\+0\.23\+0\.23\(Mistral 7B\), a small shift toward female tokens in every model\. Under the direct condition it ranges from−0\.07\-0\.07\(Qwen 2\.5 7B\) to\+0\.48\+0\.48\(LLaMA 3\.2 3B\)\. This confirms that the bias observed at the generation level \(Figure[1](https://arxiv.org/html/2610.28944#S1.F1)\) is not an artifact of decoding: the model’s first\-token distribution is already skewed before any text is produced\.

Table 4:Mean log\-odds ratio shift \(Δ​LOR\\Delta\\mathrm\{LOR\}\) for base models under direct and indirect conditions\. Probabilities are read at the first position after the priming sentence alone \(no target sentence\), so both target formats yield the same values up to numerical noise; we report the sentence\-completion rows\.

## Appendix FUse of AI Assistants

We used AI assistants for grammar and clarity checks on the manuscript and as a coding aid during experiment implementation\. AI\-generated suggestions were reviewed and edited by the authors before inclusion\.