Experiencing ownership over a dark-skinned body reduces implicit racial bias

Highlights

• Can we alter implicit racial attitudes by increasing self-other bodily overlap?

• We induced light-skinned participants to feel ownership over a dark-skinned hand.

• Ownership over a dark-skinned hand reduced negative racial attitudes to dark skin.

• A change in body ownership, rather than synchronous stimulation, drives the effect.

• Self-other overlap of body representations may play key role in social cognition.

Abstract

Previous studies have investigated how existing social attitudes towards other races affect the way we ‘share’ their bodily experiences, for example in empathy for pain, and sensorimotor mapping. Here, we ask whether it is possible to alter implicit racial attitudes by experimentally increasing self-other bodily overlap. Employing a bodily illusion known as the ‘Rubber Hand Illusion’, we delivered multisensory stimulation to light-skinned Caucasian participants to induce the feeling that a dark-skinned hand belonged to them. We then measured whether this could change their implicit racial biases against people with dark skin. Across two experiments, the more intense the participants’ illusion of ownership over the dark-skinned rubber hand, the more positive their implicit racial attitudes became. Importantly, it was not the pattern of multisensory stimulation per se, but rather, it was the change in the subjective experience of body ownership that altered implicit attitudes. These findings suggest that inducing an overlap between the bodies of self and other through illusory ownership is an effective way to change and reduce negative implicit attitudes towards outgroups.

Introduction

Embodied accounts of social cognition argue that body representations play a causal role in sociocognitive processing (e.g., Gallese, Keysers, & Rizzolatti, 2004). Neurocognitive studies into the ‘mirror neuron system’ have shown that we activate similar brain regions both when we observe a bodily state in others, and when we experience that bodily state ourselves (see Keysers & Gazzola, 2009), reflecting an overlap between self and other bodily representations in the brain. These shared bodily representations for self and other may be particularly important for empathy and other core sociocognitive processes, as they can afford us a unique, first-person understanding of the experiences of others (Gallese, 2001, Gallese, 2003).

Interestingly, the activation of shared bodily representations for self and other has been shown to be modulated by whether the other person being observed is a member of a racial ingroup or outgroup (Avenanti et al., 2010, Desy and Theoret, 2007, Gutsell and Inzlicht, 2010, Serino et al., 2009, Xu et al., 2009). For example, a recent EEG study (Gutsell & Inzlicht, 2010) showed activation over the motor cortex when participants observed an action performed by a member of their own race, but that this activation was significantly reduced when an action was performed by a member of a racial outgroup. In a single pulse TMS study, Avenanti et al. (2010) measured sensorimotor empathic brain response to the observation of another individual experiencing pain. If participants observed a painful stimulus applied to member of their own race, they showed a typical neural resonance, recruiting the same neural network as when experiencing pain themselves. However, when observing a member of a racial outgroup, this mapping of the other’s pain onto the self was absent. Furthermore, the lack of neural resonance with the racial outgroup was significantly correlated with participants’ implicit racial biases, as measured with the Implicit Association Task (IAT: Greenwald, McGhee, & Schwartz, 1998).

This not only suggests that there is a reduced activation of shared bodily representations for self and other for members of racial outgroups, but that our implicit racial attitudes affect this reduction. The more negative our implicit attitudes are towards individuals from a racial outgroup, the less overlap there is between the representation of their bodies and our own. However, no study has yet tested the bidirectionality of this relationship between racial attitudes and self-other bodily representations. Can we alter implicit racial attitudes by experimentally increasing self-other bodily overlap?

This possibility received indirect support from a recent study by Inzlicht, Gutsell, and Legault (2012), who showed that the behavioural mimicry of an individual from a racial outgroup reduced implicit racial prejudice towards that outgroup. Mimicry may lead to a blurring of the boundary between self and other (Farmer & Tsakiris, 2012), and has been shown to activate mirror neuron areas responsible for neural resonance with other’s actions (Obhi & Hogeveen, 2010). Inzlicht et al. suggested that mimicry reduced implicit prejudice by increasing self-other overlap, thus enhancing neural resonance with the racial outgroup. We endeavored to test this suggestion directly, by experimentally increasing self-other overlap and measuring its effects on racial prejudice.

One of the most viable methods for increasing self-other overlap may be to employ bodily illusions, which utilise synchronous multisensory stimulation to alter the way we represent our bodies. In the Rubber Hand Illusion (RHI: Botvinick & Cohen, 1998), seeing a rubber hand being touched in synchrony with one’s unseen hand creates a sense of ownership over the fake hand, allowing its incorporation into our body-representation (see Fig. 1A). This blurs the perceptual boundaries between self and other, increasing the similarity that participants subsequently perceive between the rubber hand and their own (Longo, Schuur, Kammers, Tsakiris, & Haggard, 2009). Interestingly, induced ownership occurs despite differences in skin colour. Farmer, Tajadura-Jimenez, and Tsakiris (2012) employed the RHI to successfully induce light-skinned Caucasian participants to incorporate a dark-skinned hand from a racial outgroup into their own body-boundaries. Therefore, the RHI is a potentially effective way to increase the overlap between representations of one’s own body and that of a member of a racial outgroup, increasing perceived similarity to the self.

Importantly, Farmer et al. (2012) also took pre- and post-RHI measures of implicit racial bias, using the IAT. No significant changes in racial attitudes were found; however, the study had a within-subjects design, in which each participant experienced RHI with both a dark-skinned and light-skinned hand in the same session. Therefore, change elicited by ownership over the dark-skinned hand may have been confounded by subsequent ownership over the light-skinned hand. Interestingly, they did find a significant relationship between the level of ownership the participants reported over both hands, and post-RHI racial attitudes. Again, however, the effect of ownership over the dark-skinned hand cannot be disentangled from the effect of ownership over the light-skinned hand in their experiment.

In the current study, we used the rubber hand illusion to induce light-skinned Caucasian participants to feel that a dark-skinned rubber hand was part of their bodies, and measured whether this could change their implicit racial biases against people with dark skin. Whilst other studies have investigated how existing social distinctions and prejudice affects the way we ‘share’ the bodily experiences of others, for example in sensorimotor mapping (Desy & Theoret, 2007), and empathy for pain (Avenanti et al., 2010), in this study we aim to experimentally change the relationship between one’s own body and a physically different body, and to quantify its effect on implicit social attitudes. We decided to solely measure implicit racial attitudes, as measuring explicit racial attitudes would leave the study vulnerable to effects of demand characteristics and social desirability. We improved upon Farmer et al.’s (2012) study by employing a methodologically rigorous approach across two experiments, measuring changes in racial attitudes after inducing ownership over either a dark-skinned, or a light-skinned hand. The between-subjects design enabled us to distinguish between the effect of ownership of the dark hand specifically from the overall ownership of both hands, and allowed us to establish the causal direction of any ownership – attitude relationship observed.

We hypothesized that the incorporation of a dark-skinned hand into the body-representation would increase self-other bodily overlap and perceived similarity, and thus reduce implicit negative attitudes towards individuals with dark skin. We tested this hypothesis across two experiments. Experiment 1 was designed to investigate how increased bodily overlap with an outgroup could affect implicit attitudes towards that outgroup. Experiment 2 aimed to further investigate the nature of this effect, elucidating whether the effect was specific to implicit attitudes towards an ‘outgroup’ skin colour, or whether it was a more general effect also affecting attitudes towards the ‘ingroup’ skin-colour.