Scaffolded Vulnerability: Chatbot-Mediated Reciprocal Self-Disclosure and Need-Supportive Interaction in Couples

TL;DR

This study introduces a chatbot with dual-layer scaffolding based on Self-Determination Theory to enhance reciprocal self-disclosure and intimacy in couples, demonstrating that relational support mediates deeper connection and perceived closeness.

Contribution

It provides empirical evidence that SDT-guided mediation in chatbots fosters human connection, offering a practical framework for AI-mediated intimacy support.

Findings

Relational scaffolding reliably increased partner-provided need support.

Enabling scaffolding alone deepened disclosure but did not increase perceived closeness.

Scaffolding buffered vitality, maintaining engagement in conversations.

Abstract

While reciprocal self-disclosure drives intimacy, digital tools seldom scaffold autonomy, competence, and relatedness -- the motivational underpinnings defined by Self-Determination Theory (SDT) that enable deep exchange. We introduce a chatbot employing dual-layer scaffolding to satisfy these needs: first providing enabling affordances (instrumental support) for vulnerability, then mediating affordances (relational support) for responsiveness. In a randomized study (N = 72; 36 couples) comparing Partner Support (PS: both layers), Direct Support (DS: enabling only), and Basic Prompt (BP: questions only), results reveal a critical distinction. While enabling affordances (PS, DS) were sufficient to deepen disclosure, only mediating affordances (PS) reliably elicited partner-provided need support and increased perceived closeness. Furthermore, controlled motivation decreased across conditions, and scaffolding buffered vitality, which remained stagnant in BP. We contribute empirical evidence that SDT-guided mediation fosters connection, offering a practical framework for designing AI-mediated conversations that support, rather than replace, human intimacy.