Summary: A replication study in psychology has found clear experimental evidence linking a person’s abstract psychological identity with their bodily awareness. Using the classic rubber hand illusion, researchers show that people with a fragile, less coherent sense of self have more malleable physical boundaries and are more likely to misattribute external objects as part of their own body.
These results strengthen the case for embodied cognition—the view that mental self-concept and bodily perception are tightly integrated—and suggest concrete clinical directions for supporting people with identity disturbances, including those diagnosed with borderline personality disorder.
Key Facts
- Embodied connection: How we think about ourselves and how we perceive our bodies are deeply interconnected. A weaker, less stable psychological sense of self corresponds with reduced baseline bodily awareness.
- Rubber hand paradigm: The study replicated an earlier pilot by testing 77 participants (ages 18–40) using the rubber hand illusion. A participant’s real hand was hidden while a gloved rubber hand was placed in view. Both the real and rubber hand were stroked with a paintbrush either synchronously or asynchronously.
- Unexpected confusion in asynchronous trials: Typical participants report ownership over the rubber hand primarily during synchronous stroking. In contrast, people with low self-concept clarity experienced bodily confusion even when the strokes were asynchronous.
- Malleable bodily self: Those most susceptible to the illusion scored lower on psychological measures of clarity, coherence, and stability of identity. Lead researchers interpret this as evidence that a porous psychological self correlates with a porous bodily boundary, making these individuals more likely to incorporate external items into their self-representation.
- Experimental support for theory: While embodied cognition is an influential theoretical framework, it has lacked systematic experimental replication. This study provides robust empirical support linking self-concept strength to vulnerability to bodily illusions.
- Clinical relevance: The finding that identity fragmentation affects physical and spatial awareness opens therapeutic possibilities. Clinicians could develop sensory- or body-based interventions to help stabilize both bodily awareness and psychological identity in clinical populations such as people with borderline personality disorder.
Source: McGill University
Summary statement: McGill researchers report that people with a less clear sense of self also tend to have diminished bodily awareness. The study supports the idea that self-perception and bodily experience are closely linked.
Beyond advancing theoretical understanding of embodied cognition—the interplay between mind and bodily awareness—these results point to practical clinical opportunities. By revealing how identity fragility carries over into sensory and spatial perception, the study suggests new routes for interventions that target both mind and body.
A more malleable self?
This study replicated and extended findings from a previous, smaller experiment led by Sonia A. Krol, who is a co-author of the current work. Seventy-seven adults from the McGill community, aged 18–40, took part in the experiment using the widely used rubber hand illusion protocol.
Each participant’s real hand was hidden behind a screen while a gloved rubber hand remained visible. To control for visual cues, both hands appeared gloved. Experimenters stroked the hidden real hand and the visible rubber hand with a paintbrush in two conditions: synchronized strokes and asynchronous strokes.
As expected, many participants reported a sense of ownership over the rubber hand during synchronous stimulation. However, Jennifer Bartz, senior author and director of the McGill Laboratory of Attachment and Prosociality, noted that a subgroup of participants experienced similar illusions during asynchronous stimulation—when most people do not.
Those who were more prone to the illusion tended to score lower on questionnaires measuring the clarity, coherence, and temporal stability of their self-concept. “This suggests these individuals have a more malleable bodily self,” Bartz said, “making them more likely to fold external elements of the environment into their sense of self even when others are not.”
How two understandings of the self go ‘hand in hand’
Embodied cognition makes evolutionary sense but has been understudied in rigorous experimental work. Willis Klein, lead author and PhD candidate in psychology, emphasized the importance of translating theory into empirical evidence.
“It’s powerful to take a strong theoretical idea and show experimental data that concretely supports it,” Klein said. The team points to follow-up questions: How does embodied cognition shape empathy? Can clinicians harness body-centered methods to strengthen identity for people with unstable self-concepts, such as those with borderline personality disorder?
Funding:
This research was supported by the Natural Sciences and Engineering Research Council and the Fonds de Recherche du Québec – Société et Culture.
Key Questions Answered:
A: The study supports the view that mind and body form a continuous, interactive system often described as embodied cognition. When a person’s mental self-concept lacks clarity and stability, the brain treats bodily boundaries as more flexible, increasing the likelihood of misinterpreting sensory input from the environment.
A: The illusion combines visual and tactile signals. When a visible rubber hand is stroked in perfect synchrony with a hidden real hand, the brain integrates the matching sights and sensations and may attribute the rubber hand to the self. The current study found that people with weaker self-concept clarity show this attribution even when stroking is asynchronous.
A: The illusion highlights a direct physical expression of identity fragmentation. If identity instability produces a porous bodily boundary, clinicians can explore body-focused therapies that strengthen interoceptive and proprioceptive awareness. Such interventions may help anchor both physical and psychological aspects of self for people living with BPD.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by the editorial team.
- Additional explanatory context was added by staff to aid reader understanding.
About this neuroscience research news
Author: Aurelie Boucher
Source: McGill University
Contact: Aurelie Boucher – McGill University
Image: The image is credited to Neuroscience News
Original Research: Closed access.
Article: “Self-concept clarity and interoceptive updating in the rubber-hand illusion: A double replication study” by Klein, W., Gregory, A. J., Krol, S. A., & Bartz, J. A., Canadian Journal of Experimental Psychology.
DOI: 10.1037/cep0000387
Abstract
Self-concept clarity and interoceptive updating in the rubber-hand illusion: A double replication study
Prediction error minimization and embodied cognition theories propose that abstract self-representations depend on models of the self as an embodied agent. Although many frameworks in psychology and cognitive science assume continuity between conceptual and bodily self, rigorous empirical tests of that continuity have been limited.
A prior study by Krol and colleagues found that individuals low in self-concept clarity (SCC) were more prone to the rubber hand illusion, notably in asynchronous conditions where the illusion is typically unwarranted. That preliminary evidence suggested a link between weak self-concept and susceptibility to bodily self-illusions.
This replication study examined SCC and the rubber hand illusion in an independent sample. Using linear mixed-effects modeling, researchers again observed that lower SCC was associated with greater embodiment of the rubber hand in the asynchronous condition. The effect also appeared in synchronous conditions, reinforcing the role of SCC in vulnerability to bodily illusions.
The paper discusses implications for social cognitive neuroscience and notes an attempted replication of a previously reported oxytocin effect on embodiment; that oxytocin effect did not replicate here, though methodological differences may explain the discrepancy.