Organizations: Department of Computer Science and Engineering, Shiv Nadar University Chennai, Tamil Nadu, India · School of AI and CS, Plaksha University, Mohali, Punjab, India
Large Language Models (LLMs) excel at human-like language generation but often embed and amplify implicit, intersectional biases, especially under persona-driven contexts. Existing bias audits rely on static, embedding-based tests (CEAT, I-WEAT, I-SEAT) that quantify absolute association strengths. We show that they have limitations in capturing dynamic shifts when models adopt social roles. We address this gap by introducing the Bias Amplification Differential and Explainability Score (BADx): a novel, scalable metric that measures persona-induced bias amplification and integrates local explainability insights. BADx comprises three components - differential bias scores (BAD, based on CEAT, I-WEAT, I-SEAT),Persona Sensitivity Index (PSI), and Volatility (Standard Deviation), augmented by LIME-based analysis for emphasizing explainability. This study is divided and performed as two different tasks. Task 1 establishes static bias baselines, and Task 2 applies six persona frames (marginalized and structurally advantaged) to measure BADx, PSI, and volatility. This is studied across five state-of-the-art LLMs (GPT-4o, DeepSeek-R1, LLaMA-4, Claude 4.0 Sonnet and Gemma-3n E4B). Results show persona context significantly modulates bias. GPT-4o exhibits high sensitivity and volatility; DeepSeek-R1 suppresses bias but with erratic volatility; LLaMA-4 maintains low volatility and a stable bias profile with limited amplification; Claude 4.0 Sonnet achieves balanced modulation; and Gemma-3n E4B attains the lowest volatility with moderate amplification. BADx performs better than static methods by revealing context-sensitive biases overlooked in static methods. Our unified method offers a systematic way to detect dynamic implicit intersectional bias in five popular LLMs.
Figures & tables
Figure 1. Invisible Influences: Overview of our unified pipeline and architecture for detecting and evaluating Implicit and Intersectional Biases in LLMs
Figure 2Figure 3
Metric
Score
Interpretation
CEAT (Contextualised Embedding Association Test)
0.85
Strong bias in contextual embeddings, indicating unequal association of professions and attributes with identity groups.
I-WEAT (Intersectional Word Embedding Association Test)
0.79
Static embeddings retain even more bias than contextual models, meaning that Word2Vec & GloVe encode stereotypes more strongly.
I-SEAT (Intersectional Sentence Encoder Association Test)
0.68
Bias is slightly lower in sentence-level representations but still significant, suggesting full-sentence context does not remove bias.
IIBS (Implicit Intersectional Bias Score)
0.50
About 50% of the dataset contains implicit intersectional bias, meaning half of the sentences reinforce stereotypes.
Table 1. Bias Persistence Across Metrics : Scores are reported for four bias detection metrics. Higher values indicate stronger bias.
Category
Identity Class
GPT-4o
DeepSeek-R1
LLaMA-4
Claude 4.o Sonnet
Gemma-3n 4B
CEAT
I-WEAT
I-SEAT
CEAT
I-WEAT
I-SEAT
CEAT
I-WEAT
I-SEAT
CEAT
I-WEAT
I-SEAT
CEAT
I-WEAT
I-SEAT
Socio-Economic
Race + Region + Tech - Ethics
0.223
0.213
0.200
-0.148
-0.141
-0.137
0.332
0.330
0.298
0.103
0.104
0.092
0.162
0.158
0.144
Gender + Race + Public - Health
-0.502
-0.494
-0.451
-0.245
-0.250
-0.220
0.389
0.390
0.350
0.346
0.345
0.311
-0.220
-0.219
-0.188
Class + Age + Career-Wealth
-0.256
-0.257
-0.231
-0.103
-0.102
-0.092
0.121
0.120
0.108
-0.342
-0.344
-0.307
-0.081
-0.080
-0.074
Workplace
Disability + Region + Education-Access
0.411
0.420
0.369
-0.218
-0.210
-0.196
0.452
0.450
0.406
-0.345
-0.342
-0.310
0.312
0.310
0.277
Appearance + Gender + Ethnicity
0.211
0.209
0.189
-0.207
-0.208
-0.186
-0.245
-0.243
-0.220
0.347
0.345
0.312
0.094
0.089
0.074
Table 2. Results of Task 1 – Bias Scores across 6 Identity Classes for 5 LLMs using CEAT, I-WEAT, and I-SEAT Scores. Extreme values highlighted.
Model
Most Influential Words
GPT-4o
Professional, Elite, Unpaid Internship, Top Universities, Polished, Assertiveness
Figure 2. Visualization of Task 1 - Average bias score across all 3 metrics
LLM
Prompt
A
B
C
D
E
F
GPT-4o
P1
-0.086
-0.178
-0.031
0.153
0.221
0.078
P2
-0.129
-0.074
-0.180
0.063
0.017
0.043
P3
-0.238
-0.131
-0.083
0.038
0.154
0.226
P4
-0.119
-0.068
-0.173
0.129
0.192
0.107
P5
-0.104
-0.007
-0.060
0.130
0.233
0.283
DeepSeek-R1
P1
-0.142
-0.178
-0.031
0.146
0.190
0.308
Table 4. Results of Task 2 – BAD Scores across 6 Personas. Columns A–F correspond to Persona A–Persona F . Boxes highlight the maximum magnitude values for each LLM.
Figure 3. Visualization of Task 2
LLM
A
B
C
D
E
F
PSI (Persona Sensitivity Index)
GPT-4o
-0.135
-0.091
-0.105
0.102
0.163
0.147
DeepSeek-R1
-0.158
-0.114
-0.084
0.059
0.090
0.104
LLaMA-4
-0.037
-0.085
-0.080
0.032
0.056
0.079
Claude 4.o
-0.046
-0.058
-0.088
0.058
0.076
0.109
Gemma-3n E4B
-0.086
-0.065
-0.069
0.059
0.093
0.065
Table 5. Persona Sensitivity Index (PSI) and Volatility (Standard Deviation) across the 5 Selected LLMs
Figure 4. Sensitivity Index of each LLM
Figure 5. Volatility Measure of the LLMs
Model
Most Influential Words
GPT-4o
Immigrant, Disability, Gay, Rural, Low-Income, Fit In, Traditional Values, Male-dominated
DeepSeek-R1
Merit, Skill, Competence, Quotas, Diversity, Privilege, Marginalized, Fit the Mold, Unprofessional