Thinner than yourself: self-serving bias in body size estimation.

The self-serving bias is the tendency to consider oneself in unrealistically positive terms. This phenomenon has been documented for body attractiveness, but it remains unclear to what extent it can also emerge for own body size perception. In the present study, we examined this issue in healthy young adults (45 females and 40 males), using two body size estimation (BSE) measures and taking into account inter-individual differences in eating disorder risk. Participants observed pictures of avatars, built from whole body photos of themselves or an unknown other matched for gender. Avatars were parametrically distorted along the thinness-heaviness dimension, and individualised by adding the head of the self or the other. In the first BSE task, participants indicated in each trial whether the seen avatar was thinner or fatter than themselves (or the other). In the second BSE task, participants chose the best representative body size for self and other from a set of avatars. Greater underestimation for self than other body size emerged in both tasks, comparably for women and men. Thinner bodies were also judged as more attractive, in line with standard of beauty in modern western society. Notably, this self-serving bias in BSE was stronger in people with low eating disorder risk. In sum, positive attitudes towards the self can extend to body size estimation in young adults, making own body size closer to the ideal body. We propose that this bias could play an adaptive role in preserving a positive body image.

Incongruent multisensory stimuli alter bodily self-consciousness: Evidence from a first-person perspective experience.

In our study, we aimed to reduce bodily self-consciousness using a multisensory illusion (MI), and tested whether this manipulation increases Self-objectification (the psychological attitude to perceive one's own body as an object). Participants observed their own body from a first-person perspective, through a head-mounted display, while receiving incongruent (or congruent) visuo-tactile stimulation on their abdomen or arms. Results showed stronger feelings of disownership, loss of agency and sensation of being out of ones' own body during incongruent compare to congruent stimulation. This reduced bodily self-consciousness did not affect Self-objectification. However, self-objectification (as measured by the appearance of control beliefs subscale of the Objectified Body Consciousness questionnaire) was positively correlated with the MI strength. Moreover, we investigated the impact of MI and Self-objectification on body size estimation. We found systematic body size underestimation, irrespective of type of stimulation or tendency to Self-objectification. These results document a simple yet effective approach to alter bodily self-consciousness, which however spare Self-objectification and body size-perception.

Up-and-left as a spatial cue of leadership.

Cues of leadership are features that signal who is (or who is expected to be) the leader in a specific context. Although their use is widespread, empirical research is scarce, especially for spatial positioning as a sign of leadership. Based on work on spatial biases, we suggest here that the upper-left corner of a page is a spatial position associated with leadership. In the present studies (N = 455), we investigated this hypothesis and showed that a layout with a photograph positioned in the upper-left corner (compared to the upper-right, lower-left, or lower-right corner) led people to infer that the person portrayed in the photograph had a leading (vs. subordinate) role in the organization. Participants also thought that the upper-left corner was the ideal spatial position to convey a leading (vs. subordinate) role in an organization. Implications of these results for symbols of leadership and spatial biases are discussed.

Self-other bodily merging in the context of synchronous but arbitrary-related multisensory inputs.

A debated issue in the multisensory literature concerns the relative contribution of bottom-up sensory components versus top-down cognitive elaborations in contributing to the rise and persistency of bodily illusion. Previous studies, for instance, have shown that simultaneity of sensory inputs and plausibility of the stimulated object play an important role in the rubber hand phenomenon, whereas violation of tactile expectancy does not disrupt the illusory feeling to own a fake hand. The present research examined this issue in the context of the "enfacement" phenomenon (i.e., self-other face-perception modification), using entirely arbitrary and non-ecological pairs of visual and tactile events. Visual and tactile stimulation was matched in terms of spatial location, but not linked by any previously learned associations, making temporal synchrony a critical binding factor. Participants received electro-tactile stimulations on their cheek, while they watched the face of a stranger illuminated on the cheek with a dot of white light. Synchronous (vs. asynchronous) stimulations yielded the enfacement effect. In addition, the stranger stimulated in synchrony was judged as more similar, physically and in terms of personality, and as closer to the self. These findings suggest that synchronous multisensory stimulation on the face can produce both perceptual and social binding, even in the absence of any previously learned associations between the stimulations.

Synchronous multisensory stimulation blurs self-other boundaries.

In a study that builds on recent cognitive neuroscience research on body perception and social psychology research on social relations, we tested the hypothesis that synchronous multisensory stimulation leads to self-other merging. We brushed the cheek of each study participant as he or she watched a stranger's cheek being brushed in the same way, either in synchrony or in asynchrony. We found that this multisensory procedure had an effect on participants' body perception as well as social perception. Study participants exposed to synchronous stimulation showed more merging of self and the other than participants exposed to asynchronous stimulation. The degree of self-other merging was determined by measuring participants' body sensations and their perception of face resemblance, as well as participants' judgment of the inner state of the other, closeness felt toward the other, and conformity behavior. The results of this study show how multisensory integration can affect social perception and create a sense of self-other similarity.