Cross-race facial recognition: evidence for encoding as a locus of the cross-race effect

Abstract

The present study investigated the cross-race effect (CRE) in NZ Maori and Pakeha adults. The CRE refers to the frequently-demonstrated phenomenon of better recognition for faces of a person's own race In contemporary contexts, 'ethnicity' is favoured over the term ‘race'. The current Thesis retains the word 'race' to refer to ethnicity of a person to maintain consistency with the body of literature under review. than for faces for another race. Several hypotheses have been put forward to explain the CRE, the majority implicating a perceptual or encoding locus of the effect. However, virtually all studies to date have confounded perceptual and memorial aspects of the recognition tasks employed to investigate the CRE. In the current study New Zealand Pakeha and Maori subjects identified Pakeha faces and Maori faces in a delayed matching-to-sample task (DMTS) with four retention intervals (RI) that varied from 0.1 to 20 s. This task theoretically allows separation of perceptual (initial encoding) and memorial processing. Transformation of a facial stimulus from front view at time of encoding to 3/4 profile view at time of recognition test was also investigated by the DMTS task. Measures of recognition accuracy and speed of matching the facial stimuli were assessed at each of the four RIs. Subjects in the DMTS task also indicated on two Likert-type scales how much contact/experience they had with both Maori and Pakeha persons. Results from the DMTS task demonstrated a variant of the CRE in that Maori subjects matched Maori faces more accurately and more quickly than they matched Pakeha faces. On the other hand, Pakeha subjects matched faces of both ethnic groups at similar levels of speed and accuracy. RI influenced performance in terms of both speed and accuracy with a consistent decline in performance as RI duration increased. The CRE did not interact with RI, providing support for a perceptual explanation for the source of the CRE, rather than a short-term memorial deficit. Transformation of facial pose increased task difficulty: Overall, faces transformed to 3/4 profile view were more poorly matched in terms of both speed and accuracy than faces which remained in front view pose. An interaction between race of face and transformation in the reaction time analyses suggests that speed measures may be more sensitive to subtle increases in task difficulty than error rates. The near-zero correlation between recognition accuracy and self-reported experience with other-race persons provides no support for a major theory concerning the source of the CRE, namely the contact hypothesis.