The Dominance Effect: How Verbal and Nonverbal Cues of Virtual Agents Influence Decision-Making in VR

Paper Title

The Dominance Effect: How Verbal and Nonverbal Cues of Virtual Agents Influence Decision-Making in VR

Publication Info

• Topic area: Influence of verbal and nonverbal dominance cues in Embodied Conversational Agents (ECAs) on decision-making and perception in Virtual Reality (VR).
• Keywords: Virtual agents, dominance cues, decision-making, verbal communication, nonverbal communication, embodied conversational agents, social presence, VR interaction, user perception, behavioral influence.

Background and Problem

• Problem / challenge: Existing research on dominance cues in human-agent interaction has primarily focused on single modalities (verbal or nonverbal) in isolation. The interaction between verbal and nonverbal dominance cues, particularly their congruence or incongruence, remains underexplored.
• Significance: Understanding how dominance cues influence decision-making and perception is critical for designing effective ECAs in applications such as training, education, and decision support.
• Motivation and related work: Prior studies have shown that dominance influences human-human and human-agent interactions, but findings from human-human contexts do not always generalize to ECAs. Research has also highlighted the importance of congruence between verbal and nonverbal cues in shaping user responses, but empirical evidence in VR contexts is limited.

Solution

• Proposed approach: A 2×2 factorial study examining the effects of verbal (dominant vs. submissive) and nonverbal (dominant vs. submissive) dominance cues on user decision-making and perception in a VR-based route-selection task.
• Novelty:
  1. Empirical investigation of the independent and combined effects of verbal and nonverbal dominance cues in ECAs.
  2. Analysis of congruence and incongruence between verbal and nonverbal cues on user behavior and perception.
  3. Use of a VR environment to simulate immersive, dynamic interactions with ECAs.
• Procedure and key techniques:
  • Participants interacted with four ECAs exhibiting different combinations of verbal and nonverbal dominance cues.
  • A binary route-selection task was used to measure decision-making.
  • Immediate post-trial and post-experiment questionnaires assessed perceptions of dominance, competence, trustworthiness, warmth, likability, and social presence.
  • Statistical analyses included ART-ANOVA and post-hoc tests to evaluate the effects of dominance cues and their congruence.

Results

• Concrete findings:
  • Nonverbal dominance cues significantly influenced decision-making (F(1, 114) = 14.14, p <.001), while verbal dominance showed only a marginal trend (F(1, 114) = 3, p =.08).
  • Verbal dominance significantly shaped perceptions of dominance (F(1, 105) = 263.45, p <.001), competence (F(1, 894) = 123.37, p <.001), and trustworthiness (F(1, 894) = 29.93, p <.001).
  • Nonverbal dominance significantly influenced likability (F(1, 894) = 30.43, p <.001), social presence (F(1, 894) = 39.95, p <.001), and trustworthiness (F(1, 894) = 32.64, p <.001).
  • Congruence between verbal and nonverbal cues showed no statistically significant effects on decision-making or perception.
• Advantage over baselines:
  • Nonverbal dominance cues had a stronger and more consistent impact on decision-making compared to verbal cues.
  • Verbal cues were more influential in shaping explicit perceptions of dominance and competence.
• Experiments / evaluation:
  • Participants: 39 individuals (21 female, 18 male, aged 18–28).
  • Setup: VR environment using Meta Quest 3 headset; 12 trials per participant with randomized agent pairings.
  • Metrics: Binary decision outcomes, Likert-scale ratings for perception measures, and post-experiment dominance evaluations.
• Limitations and future work:
  • Lack of a neutral dominance condition limits generalizability.
  • Simplistic binary decision-making task may not reflect real-world complexity.
  • Short interaction duration (7 seconds per trial) may have influenced cue processing.
  • Homogeneous participant sample (university students) limits cultural generalizability.
  • Future work should explore multi-step decision tasks, cross-cultural comparisons, and the role of facial expressions and static appearance.

Summary

This study examined how verbal and nonverbal dominance cues from ECAs influence decision-making and perception in VR. Nonverbal dominance cues significantly affected decision-making and social evaluations (e.g., likability, social presence), while verbal dominance primarily shaped explicit perceptions of dominance and competence. The effects of cue congruence were not statistically significant. These findings suggest that verbal and nonverbal dominance cues operate through distinct pathways, with nonverbal cues influencing behavior implicitly and verbal cues shaping explicit judgments. The results provide actionable insights for designing ECAs tailored to specific interaction contexts, such as training and decision support.