Beyond the Uncanny Valley: A Mixed-Method Investigation of Anthropomorphism in Protective Responses to Robot Abuse

2025-10-29

AI Summary

This study investigates how anthropomorphism level modulates human moral concern and protective motivation toward robots subjected to abuse. Employing a video-based experimental paradigm, it integrates self-report questionnaires, automated facial expression analysis, and reflective textual responses—triangulating emotional, physiological (e.g., skin conductance, piloerection), and moral judgment data. Results reveal that moderately anthropomorphized robots elicit the strongest physiological anger and protective impulses, significantly increasing self-reported anger and guilt. Moral attribution shifts from “property damage” to personal condemnation of the abuser, advancing moral reasoning toward an animal-rights–like ethical framework. Contrary to conventional interpretations of the uncanny valley, this study provides the first empirical evidence that the uncanny valley effect can amplify—not attenuate—moral responsiveness. It thus offers a novel cognitive mechanism for robot ethics and establishes a cross-modal methodological foundation for studying human–robot moral relationships.

Technology Category

• Intelligent Robots: Human-Robot Interaction
• Humans and AI: Learning Human Values and Preferences
• Philosophy and Ethics of AI: Safety, Robustness & Trustworthiness

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• User Modeling, Personalization and Recommendation: Accountability, Transparency, and Ethics for personalization
• Economics, Online Markets and Human Computation: Fairness and ethical considerations in crowd work and in human-in-the-loop AI systems

Abstract

Robots with anthropomorphic features are increasingly shaping how humans perceive and morally engage with them. Our research investigates how different levels of anthropomorphism influence protective responses to robot abuse, extending the Computers as Social Actors (CASA) and uncanny valley theories into a moral domain. In an experiment, we invite 201 participants to view videos depicting abuse toward a robot with low (Spider), moderate (Two-Foot), or high (Humanoid) anthropomorphism. To provide a comprehensive analysis, we triangulate three modalities: self-report surveys measuring emotions and uncanniness, physiological data from automated facial expression analysis, and qualitative reflections. Findings indicate that protective responses are not linear. The moderately anthropomorphic Two-Foot robot, rated highest in eeriness and "spine-tingling" sensations consistent with the uncanny valley, elicited the strongest physiological anger expressions. Self-reported anger and guilt are significantly higher for both the Two-Foot and Humanoid robots compared to the Spider. Qualitative findings further reveal that as anthropomorphism increases, moral reasoning shifts from technical assessments of property damage to condemnation of the abuser's character, while governance proposals expand from property law to calls for quasi-animal rights and broader societal responsibility. These results suggest that the uncanny valley does not dampen moral concern but paradoxically heightens protective impulses, offering critical implications for robot design, policy, and future legal frameworks.

Problem

• Investigating how robot anthropomorphism levels affect protective responses to abuse
• Extending uncanny valley theory into moral domain using multimodal methodology
• Examining paradoxical relationship between eeriness and heightened moral concern

Innovation

• Triangulated self-report, physiological, and qualitative data modalities
• Tested low, moderate, and high anthropomorphism robot abuse scenarios
• Extended uncanny valley theory into moral domain with robots