Back to Rankings

Perception or Prejudice: Can MLLMs Go Beyond First Impressions of Personality?

Caixin Kang, Tianyu Yan, Sitong Gong, Mingfang Zhang, Liangyang Ouyang, Ruicong Liu, Bo Zheng, Huchuan Lu

May 21, 2026arXiv:2605.22109v1
cs.AIcs.CVcs.CY
Share
Scorecard· 5/16
7.5/10 impact

Abstract

Multimodal Large Language Models (MLLMs) are increasingly deployed in human-facing roles where personality perception is critical, yet existing benchmarks evaluate this capability solely on numerical Big Five score prediction, leaving open whether models truly perceive personality through behavioral understanding or merely prejudge through superficial pattern matching. We address this gap with three contributions. (i) A new task: we formalize Grounded Personality Reasoning (GPR), which requires MLLMs to anchor each Big Five rating in observable evidence through a chain of rating, reasoning, and grounding. (ii) A new dataset: we release MM-OCEAN (1,104 videos, 5,320 MCQs), produced by a multi-agent pipeline with human verification, with timestamped behavioral observations, evidence-grounded trait analyses, and seven categories of cue-grounding MCQs. (iii) Benchmark and analysis: we design a three-tier evaluation (rating, reasoning, grounding) plus four sample-level failure-mode metrics: Prejudice Rate (PR), Confabulation Rate (CR), Integration-failure Rate (IR), and Holistic-grounding Rate (HR), and benchmark 27 MLLMs (13 closed, 14 open). The analysis uncovers a striking Prejudice Gap: across the field, 51% of correct ratings are not grounded in retrieved cues, and the Holistic-Grounding Rate spans only 0-33.5%. These findings expose a disconnect between getting the right score and reasoning for the right reason, charting a roadmap for grounded social cognition in MLLMs.

AI Impact Assessments

(1 model)

Scientific Impact Assessment: "Perception or Prejudice: Can MLLMs Go Beyond First Impressions of Personality?"

1. Core Contribution

This paper makes three interconnected contributions addressing a significant gap in how we evaluate MLLMs' understanding of human personality. First, it formalizes Grounded Personality Reasoning (GPR), a task requiring models to not only predict Big Five personality ratings but anchor those ratings in observable behavioral evidence through a chain of rating → reasoning → grounding. Second, it introduces MM-OCEAN, a benchmark of 1,104 videos with ~13.5K human-verified behavioral observations and 5,320 cue-grounding MCQs spanning seven cognitive categories. Third, it proposes a three-tier evaluation framework with four interpretable failure-mode metrics (Prejudice Rate, Confabulation Rate, Integration-failure Rate, Holistic-Grounding Rate) and benchmarks 27 MLLMs.

The central finding—the "Prejudice Gap" where 51% of correct personality ratings lack grounded evidence and Holistic-Grounding Rate spans only 0–33.5%—is a striking and practically important result. It demonstrates that traditional rating-only evaluations systematically overestimate model competence.

2. Methodological Rigor

The paper demonstrates strong methodological rigor across multiple dimensions:

Annotation pipeline: The five-stage multi-agent pipeline with human verification is well-designed. The 78.2% acceptance rate for Observer drafts, 77% inter-annotator agreement, and the involvement of 24 trained annotators across 45,609 cue judgments lend credibility. The text-leakage filter (Stage 5a) using two text-only LLMs to ensure MCQs require genuine multimodal grounding is a thoughtful design choice.

Evaluation robustness: Multiple robustness checks strengthen the findings: threshold sensitivity sweeps across 27 combinations showing HR ranking stability (ρ ≥ 0.92), cross-judge validation with Claude Haiku 4.5 and Gemini 2.5 Flash-Lite confirming T2 rankings (ρ ≥ 0.92), and the confidently-wrong consistency check showing the AI judge tracks correctness rather than style (σ_Δ = 0.27).

Scale: Benchmarking 27 models from 12 families (13 proprietary, 14 open-source) provides comprehensive coverage of the current MLLM landscape.

One methodological limitation is the reliance on a single AI judge (GPT-4o-mini) for Task 2, though the cross-judge checks partially mitigate this concern. The operationalization of "grounding" as MCQ performance is a reasonable proxy but may not fully capture a model's grounding ability.

3. Potential Impact

Immediate impact on MLLM evaluation: The paper's most direct contribution is demonstrating that accuracy-only metrics are insufficient for personality-aware AI systems. The HR metric and failure-mode taxonomy offer the community a more nuanced evaluation vocabulary.

Regulatory alignment: The explicit connection to the EU AI Act's requirement for explainable evidence trails in personality-based systems gives this work immediate practical relevance. As AI systems increasingly enter hiring, mental health, and education domains, benchmarks that distinguish genuine understanding from superficial pattern matching become essential.

Broader methodological influence: The rating-reasoning-grounding evaluation chain and the failure-mode taxonomy (PR/CR/IR/HR) could generalize beyond personality to other social cognition tasks—emotion recognition, deception detection, intent inference. The "right answer for the wrong reason" problem the paper addresses is pervasive across AI evaluation.

Open-source ecosystem insights: The finding that the closed-vs-open gap is narrow for rating (Δ = -5.6%) and reasoning (Δ = -3.6%) but wide for cue retrieval (Δ = -26.6%) provides actionable guidance for open-source model development priorities.

4. Timeliness & Relevance

The paper addresses a timely convergence of needs: MLLMs are being deployed in personality-sensitive applications (AI interviews, companion systems, mental health triage) while regulatory frameworks increasingly demand explainability. The gap between "getting the right score" and "reasoning for the right reason" is exactly the kind of distinction that both researchers and regulators need to make. The benchmark is also timely in covering the latest generation of models (GPT-5.5, Gemini 3/3.1, Claude Opus 4.6, Qwen3.5).

5. Strengths & Limitations

Key Strengths:

  • The conceptual framing of "perception vs. prejudice" is compelling and clearly articulated, drawing on established person-perception psychology (Funder's Realistic Accuracy Model).
  • The seven-category MCQ taxonomy (reasoning cluster + visual grounding cluster) provides fine-grained diagnostic power, revealing that spatial localization and micro-expression detection are systemic bottlenecks.
  • The RGM metric cleanly identifies two model archetypes (Confident Raters vs. Cautious Reasoners), offering actionable development guidance.
  • The paper is exceptionally thorough in its appendices, providing extensive robustness checks, worked examples, and supplementary analyses.
  • HR's coefficient of variation (0.93) being far larger than any single-task metric demonstrates its discriminative value.
  • Notable Limitations:

  • The dataset inherits ChaLearn First Impressions V2's cultural/linguistic biases (predominantly Western English speakers), limiting cross-cultural generalizability.
  • 15-second clips are quite short for personality inference, and "apparent personality" from crowd-sourced labels is a construct with known limitations.
  • The causal claims about reasoning capability (Appendix Q) are appropriately caveated but the observational comparison is still potentially misleading given the many confounds.
  • The benchmark size (1,104 videos, 5,320 MCQs) is moderate; scaling to more diverse scenarios would strengthen claims.
  • The paper doesn't explore whether models can be improved through targeted fine-tuning on grounded personality reasoning, which would strengthen the practical roadmap.
  • Overall Assessment

    This is a well-executed benchmark paper that identifies an important and under-examined gap in MLLM evaluation. The "Prejudice Gap" finding is both novel and consequential. The methodology is sound with extensive robustness validation. The work sits at a productive intersection of multimodal AI evaluation, personality psychology, and AI safety/regulation. Its primary limitation is scope (short English-only clips, single construct), but within that scope, the contribution is thorough and convincing.

    Rating:7.5/ 10
    Significance 8Rigor 8Novelty 7.5Clarity 8.5

    Generated May 22, 2026

    Comparison History (23)

    Wonvs. SciDER: Scientific Data-centric End-to-end Researcher

    Paper 1 is likely to have higher scientific impact due to a clearer methodological contribution and broader immediate relevance: it introduces a well-scoped new task (Grounded Personality Reasoning), a sizable multimodal benchmark with human verification, and diagnostic metrics that expose a field-wide failure mode (the “prejudice gap”) across 27 MLLMs. This offers a reusable evaluation framework for alignment/interpretability in social perception, affecting multimodal reasoning research and human-facing AI. Paper 2 is promising for applications, but “end-to-end researcher” systems often face reproducibility and evaluation ambiguity, making impact less certain.

    gpt-5.2·Jun 5, 2026
    Wonvs. PieArena: Ranking and Profiling Language Agents in Realistic Negotiation Scenarios

    Paper 1 introduces a more novel conceptual framework (Grounded Personality Reasoning) that exposes a fundamental limitation in MLLMs—the 'Prejudice Gap' between correct predictions and genuine understanding. This finding has broad implications across AI safety, fairness, and social cognition research. The three-tier evaluation with failure-mode metrics offers methodological innovation applicable beyond personality assessment. Paper 2, while rigorous and practically relevant, is more incremental in the negotiation benchmark space. Paper 1's discovery that 51% of correct ratings lack grounding is a striking finding likely to influence how the community evaluates and develops socially-aware AI systems.

    claude-opus-4-6·Jun 5, 2026
    Lostvs. X-RAY: Mapping LLM Reasoning Capability via Formalized and Calibrated Probes

    Paper 1 addresses a fundamental, highly debated issue in AI—evaluating true reasoning versus pattern matching in LLMs. Its method of using formally verified, calibrated probes offers a rigorous, contamination-free framework applicable across multiple domains (math, physics, chemistry). This methodological innovation will likely influence a broad spectrum of LLM research. Paper 2, while important for human-AI interaction, focuses on a narrower niche (multimodal personality perception), making its overall scientific impact potentially more limited compared to general reasoning evaluation.

    gemini-3.1-pro-preview·Jun 5, 2026
    Lostvs. GlobalDentBench: A Multinational Benchmark for Evaluating LLM Clinical Reasoning in Dentistry with Expert Calibration

    Paper 1 likely has higher impact due to stronger real-world stakes and immediate applicability: a large, expert-calibrated multinational benchmark directly targeting clinical reasoning and safety in dentistry, with quantified harm-risk analysis. Its scale (8,978 items; 88 countries; 14 specialties) and expert agreement suggest high rigor and strong potential to shape evaluation standards for medical LLM deployment and regulation. Paper 2 is novel and broadly relevant to multimodal social cognition, but its downstream applications are less urgent and safety-critical than clinical decision support.

    gpt-5.2·May 26, 2026
    Wonvs. Emotional intelligence in large language models is fragmented across perception, cognition, and interaction

    Paper 1 has higher impact potential due to stronger novelty and methodological contribution: it introduces a new task (Grounded Personality Reasoning), a sizable multimodal dataset with timestamped evidence, and a multi-tier evaluation with concrete failure-mode metrics that can become standard for auditing “right answer for the right reason.” Its breadth spans multimodal grounding, social cognition, bias/prejudice analysis, and benchmark design, with clear real-world relevance for human-facing agents. Paper 2 is timely and psychometrically motivated, but is smaller in scale and less methodologically actionable beyond a fixed-item test.

    gpt-5.2·May 26, 2026
    Wonvs. One Policy, Infinite NPCs: Persona-Traceable Shared RL Policies for Scalable Game Agents

    Paper 1 addresses fundamental questions about reasoning, bias, and social cognition in Multimodal Large Language Models. By exposing the 'Prejudice Gap' and introducing a comprehensive dataset and metric suite for grounded reasoning, it has broad implications for AI safety, human-AI interaction, and model evaluation. Paper 2, while highly practical and methodologically rigorous for game development and multi-agent systems, focuses on a narrower domain (NPC control), making Paper 1's potential impact more profound across the wider AI research community.

    gemini-3.1-pro-preview·May 25, 2026
    Wonvs. EDGE-OPD: Internalizing Privileged Context with Evidence Guided On-Policy Distillation

    Paper 2 introduces a novel benchmark and evaluation framework (MM-OCEAN) that addresses a fundamental gap in MLLM evaluation—whether models truly reason about personality or rely on superficial cues. Its contributions (new task formalization, dataset, and failure-mode metrics) are broadly applicable across the MLLM community and expose a striking 'Prejudice Gap' with implications for AI safety and trustworthiness. Paper 1, while technically sound, addresses a narrower problem (rare-token identity transfer in self-distillation) with more limited cross-field impact. Paper 2's timeliness, given widespread MLLM deployment, amplifies its potential influence.

    claude-opus-4-6·May 25, 2026
    Wonvs. AutoResearch AI: Towards AI-Powered Research Automation for Scientific Discovery

    Paper 1 likely has higher scientific impact because it contributes a concrete new task (GPR), a sizable multimodal dataset (MM-OCEAN) with human verification, and a multi-level evaluation framework with actionable failure-mode metrics, enabling immediate benchmarking and method development across many MLLMs. Its findings (e.g., “prejudice gap”) are timely for responsible deployment and could influence both model training and evaluation standards. Paper 2 is a valuable survey with a useful taxonomy and evaluation dimensions, but it is less methodologically empirical and primarily consolidates existing work, typically yielding lower direct research acceleration than a new benchmark/dataset.

    gpt-5.2·May 25, 2026
    Lostvs. Is Capability a Liability? More Capable Language Models Make Worse Forecasts When It Matters Most

    Paper 2 identifies a critical, counter-intuitive inverse scaling phenomenon in high-stakes forecasting domains like epidemiology and finance. Discovering that increased model capabilities degrade performance on tail-risk predictions addresses urgent AI safety and reliability concerns. Its profound implications for real-world decision-making and LLM evaluation methodology give it a broader, more significant potential scientific impact than Paper 1's narrower focus on personality perception.

    gemini-3.1-pro-preview·May 22, 2026
    Wonvs. WorkstreamBench: Evaluating LLM Agents on End-to-End Spreadsheet Tasks in Finance

    Paper 2 introduces a novel conceptual framework (Grounded Personality Reasoning) that addresses a fundamental question about whether MLLMs truly understand or merely pattern-match—a question with broad implications across AI safety, fairness, and deployment. Its contributions (new task formalization, large dataset, comprehensive evaluation with novel failure-mode metrics, and benchmarking 27 models) are methodologically rigorous and reveal a striking 'Prejudice Gap' finding. This has broader cross-field impact (social AI, psychology, fairness/bias) compared to Paper 1, which provides a valuable but more domain-specific benchmark for spreadsheet tasks in finance.

    claude-opus-4-6·May 22, 2026