Wong, Hoo Keat
(2020)
The own-race bias for face recognition in a multiracial country.
PhD thesis, University of Nottingham.
Abstract
The own-race bias (ORB) is a well-documented phenomenon whereby people are more accurate at recognising faces from their own-race group compared to faces from different race groups (Meissner & Brigham, 2001). While empirical studies have reported the robustness of the ORB across racial groups, the finding that the ORB is negatively related to exposure to other-race individuals suggests that may not necessarily apply to individuals who were born and have lived in a multiracial society. This thesis fills a gap in the ORB literature by examining the role of multiracial immersion experience as well as potential perceptual/attentional mechanisms in modulating the ORB by employing a series of face memory and face perceptual tasks on different racial groups (i.e. Malaysian-Malay, Malaysian-Chinese, Malaysian-Indian, African and Western-Caucasian individuals).
In Experiment 1, I demonstrated that the ORB in face memory was pronounced not only in Western-Caucasian participants, but also in Malaysian participants (Malay, Chinese, and Indian) who were raised in a racially diverse environment, implying that growing up in a profoundly multiracial society does not eliminate the ORB. In Experiment 2, I found significant correlations between memory performance for learned target faces and facial distinctiveness; most importantly, own-race faces benefited more from this distinctiveness effect than other-race faces across the four race groups. These findings fit well with Valentine’s (1991) face-space model that dimensions of face space are optimised for own-race faces, and the ORB is likely to be attributable to the inefficiency in the use of norm-based coding for other-race faces.
Using a procedure identical to Experiment 1, I observed a significantly greater increment in recognition performance for other-race faces than for own-race faces when the external features (e.g., facial contour and hairline) were presented along with the internal features in Experiment 3. This finding supports the notion that different processing mechanisms are involved for own- and other-race faces, with internal features of own-race faces being processed more effectively whereas external features dominate representations of other-race faces.
In Experiment 4, I adopted a cross-cultural design where Malaysian-Chinese, African, European-Caucasian and Australian-Caucasian participants performed four different tasks: (1) yes-no face recognition, (2) composite, (3) whole-part and (4) global-local tasks. Each face task was completed with unfamiliar own- and other-race faces. Although I detected a robust ORB effect in recognition accuracy, the occurrence of holistic processing for other-race faces did not lead to a smaller ORB in any of the four race groups. These unexpected results cast doubt on the holistic account of the ORB and support an alternative interpretation that the ORB cannot be fully accounted for by a reduced inability to process other-race faces holistically.
Experiment 5a and 5b were designed to test the hypothesis that directing first fixations to diagnostic features would reduce the ORB while taking the race of both face stimuli and of observers into account. Results showed that cueing participants to fixate more on the other-race diagnostic features that they would not normally fixate upon does not remove the ORB, suggesting that the ORB is not solely attributable to general lack of attention towards diagnostic features.
By the means of a gaze-contingent stimulus presentation, Experiment 6 investigated whether, and if so, to what extent restricting facial information outside/inside central vision affects face matching accuracy for own- and other-race faces. Results showed that, regardless of the race of the input face, participants’ performance level decreased when they were forced to extract the facial information feature-by-feature than when they could process all features at once holistically. This favours the view that the looking strategies (holistic vs. featural) dedicated to the extraction of facial information from own-race and other-race faces are flexible in the face matching task.
Contrary to the contact hypothesis, it appears that Malaysians’ substantial everyday exposure to different races does not lead to a broadly-tuned representation that accommodates multiple other-race faces. Collectively, my results converge with recent literature to suggest that perceptual experience shapes our ability to recognise own- and other-race faces but there is relatively little plasticity in face recognition in adulthood (e.g., Singh, Loh, & Xiao, 2017; Tree, Horry, Riley, & Wilmer, 2017). That is, interracial contact in adulthood is ineffective for improving other-race face recognition. The current findings imply that the cause of the ORB, at least for Malaysian young adults living in a multiracial environment, is a relative lack of perceptual experience in childhood, rather than a lack of motivation to individuate other-race people. Future research is required to directly address whether, and if so, how early perceptual experience with own- versus other-race faces and development interact to modulate the plasticity of ORB in adulthood.
Actions (Archive Staff Only)
 |
Edit View |
Tools
Tools
![[img]](/style/images/fileicons/application_pdf.png)