After learning to identify with someone else’s face, do people think their appearance has changed?

Past research has shown that it's possible to hack our sense of our own bodies in bewildering ways, such as perceiving another person's face as our own by stroking both in synchrony. These body illusions can alter our sense of self at a psychological level too. For example, embodying a child-sized body in a virtual reality environment leads people to associate themselves with child-like concepts. Can such effects also operate in the opposite direction, from the psychological to the physical? A new paper published in the Quarterly Journal of Experimental Psychology aimed to find out by seeing if shifting people's sense of self at a psychological level warped their sense of their facial appearance.

Sophie Payne's team at Royal Holloway, University of London manipulated their participants' sense of self by repeatedly presenting them with a black and white cropped photo of a gender-appropriate face that was labelled "self", and with two other face images that were labelled as "friend" and "stranger". To consolidate these associations, the researchers then tested the participants, repeatedly showing them one of the earlier faces together with the correct label used earlier or the wrong label, and the participants had to say each time whether the label matched the face or not.

As the test went on, the participants became especially quick at spotting when the "self face" was correctly labelled as "self", just as the researchers hoped would happen. This suggests that the previously unknown face had been incorporated into their self concept, at least temporarily. Think of it as a weaker version of the way we are particularly sensitive to any sounds that resemble our name, even against the hubbub of a cocktail party.

Having incorporated this face into their self-concept, did the participants view their facial appearance any differently? To address this, the researchers presented the participants with 100 faces and asked them to rate how similar each face was to their own. Fifty of the faces were blends of their own real face with the "stranger" face from earlier, and another 50 blended their real face with the "self face" paired earlier with their self concept.

The participants had actually completed this resemblance task earlier, before they'd learned to associate the "self face" with their self concept. The crucial test was whether, now that they'd learned to associate themselves with the "self face", they would see themselves as resembling that face physically, more so than they had done earlier. Payne's team predicted that they would, but in fact the results showed that this hadn't happened. Identifying themselves with the face hadn't made them believe that they looked like the face.

Payne's prediction was credible partly because we know the psychological self is malleable, body perception is malleable, and changes to body perception usually result in shifts in sense of self. Furthermore, and making this new result extra surprising, psychological influences have already been shown to affect our judgments about the physical appearance of our own face.

For example, a study from 2014 showed that people were more likely to say that they resembled a face that reflected a blend of their own face with someone else's, when that other face belonged to a trustworthy partner in an earlier trading task rather than a cheat. Essentially, that result showed that the lines between self and other can be easily blurred, unlike in the current study. What gives?

The non-significant result in the current study may have uncovered the limits to these kinds of blurring effects. The findings suggest that it may be quite easy to adapt our self-concept, for example attuning us to identify with a new nickname or onscreen avatar, but that for this process to go deeper and influence how we perceive our own physical appearance, we need a more motivated, involving, and perhaps social context, like being betrayed or treated loyally.

The new hypothesis, then, is that we are engineered to perceptually link – or distance ourselves – from those who have helped or wronged us, and that the heat of social emotion is the soldering iron that fixes these connections fast. Further research will tell.

Further reading

Payne, S., Tsakiris, M., & Maister, L. (2016). Can the self become another? Investigating the effects of self-association with a new facial identity The Quarterly Journal of Experimental Psychology, 1-13 DOI: 10.1080/17470218.2015.1137329