Self-unity

What makes us who we are? Is it the physical body we wake up in each morning and use to navigate the world, or is it the collection of thoughts, beliefs, and self-perceptions that define us as individuals—with specific traits, abilities, and social identities? Or is it a combination of both? And if so, how does a unified sense of self emerge from this blend of bodily sensations and conscious beliefs?

We explored these questions through a series of behavioral experiments examining how altering body perception can influence core aspects of self-concept, including gender identity and beliefs about one’s own personality.

In one study, we used a perceptual illusion to make pairs of friends feel as though they had swapped bodies. During this illusion, participants described their own personality traits in ways that were more similar to how they had previously rated their friend’s personality.

In another study, we disrupted the sense of body ownership by using asynchronous visuotactile stimulation, making participants feel less connected to their own bodies. This led to a more fragmented and less coherent structure in how they described their personality traits.

Finally, we showed that a perceptual illusion of having the opposite-sex body was associated with a shift toward more balanced identification with both genders and less gender-stereotypical beliefs about own personality characteristics, as indicated by subjective reports and implicit behavioral measures. 

Together, these findings highlight the flexibility and interconnection between the bodily and conceptual aspects of the sense of self, which has important implications for dissociative experiences and overall mental health.

Full texts:

Tacikowski, P., Weijs, M., Ehrsson, H. H. (2020). Perception of our own body influences self-concept and self-incoherence impairs episodic memory, iScience, 23: 101429. (PDF)

Tacikowski, P. & Ehrsson, H.H. (2024). Bodily disownership is associated with self-concept fragmentation. 28: 112805. (PDF)

Tacikowski, P., Fust, J., Ehrsson, H.H., (2020). Fluidity of gender identity induced by illusory body-sex change. Scientific Reports, 10: 14385. (PDF)