Beyond Face Value: Visual and Auditory Signals in Human and Machine Trust Judgments

Abstract

As conversational agents become increasingly multimodal, they invite human-like evaluations—especially in trust-sensitive contexts. Building on the human tendency to form rapid judgments from subtle visual and auditory cues, we explore how trust is constructed from faces and voices. In a behavioral experiment, 150 participants rated bimodal stimuli across four trust congruence conditions. We then trained a multimodal model using HuBERT and ResNet-50 with late fusion to predict trust scores. To examine alignment between human and model judgments, we applied Permutation Feature Importance (PFI) to compare the most influential features. Our results highlight the dominance of auditory cues in both human and model trust evaluations, while revealing subtle but meaningful differences in feature weighting across modalities and conditions.

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Citations
Research
Paper Only

Study specs

Behavioral experiment with trust ratings of bimodal stimuli across four trust congruence conditions, combined with a multimodal model trained using HuBERT and ResNet-50 with late fusion, analyzed using Permutation Feature Importance (PFI).

Sample Size
N=150
Study Type
Experimental Study
Year
2025
Human Data Platform
Prolific

Measured Outcomes

The construction of trust from visual and auditory signals in both humans and multimodal models, focusing on modality dominance and feature weighting.

Peer Review & Critical Discussion

3 threads

Potential Selection Bias in 2023 Cohort

DSJDr. Sarah J.
Verified PhD Candidate
12 replies

The participant pool shows a concerning overrepresentation of users from high-income demographics. Looking at Table 3, we can see that 78% of respondents had annual incomes above $75k, which significantly limits the generalizability of these findings to broader populations.

2 hours ago

Non-naive Participants Issue

MCM. Chen (OpenAI)
Data Scientist
8 replies

I've noticed a methodological concern regarding participant naivety. Given that Prolific users often complete multiple studies, there's a real risk that participants had prior exposure to similar experimental paradigms, which could confound the results.

5 hours ago

RLHF Applicability to This Study Design

PRWProf. R. Williams
Verified Researcher
15 replies

The implications for RLHF training pipelines are understated. If we accept the authors' conclusions about preference stability, this has direct consequences for how we should structure reward model training. The temporal decay effect described in Section 4.2 is particularly relevant.

1 day ago

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