Cross-Race Effect Reduction: Insights from Eye-Tracking and Social Background Analyses

The cross-race effect (CRE) is a phenomenon where people are better able to remember faces of their own race. Studies show that the CRE can be reduced by making participants aware of the effect, and by asking them to pay close attention to cross-race faces during the encoding phase. The objectives of this study were to reduce the CRE effect, to track eye movement, and to gather information of social background to further understand the CRE process. Data collected from 77 participants confirmed the CRE. However, the manipulation applied to the experimental group failed to improve the recognition performance of cross-race faces, suggesting that participants engaged in an ineffective encoding process. Eye tracker data confirmed previous findings and showed: less and longer fixations when looking at cross-race faces, and higher number of fixations in the areas of the eyes, nose, and mouth. Finally, the relationship between incremental experience with cross-race faces and a reduction of the CRE was inconclusive due to selfreporting issues. CROSS-RACE EFFECT, EYE-TRACKING AND SOCIAL BACKGROUND 3 Cross-Race Effect Reduction: Insights from Eye-Tracking and Social Background Analyses The cross-race effect (CRE) is a well-known phenomenon where people are better at remembering faces of their own race. There has been a lot of research performed on this topic since it was first introduced by Feingold (1914). Feingold asserted that cross-race faces tend to look alike, unless people are familiarized, usually from a young age, with faces of other races. Furthermore, own-race faces are generally perceived as being more memorable and familiar than faces of other races, and these subjective appreciations, though automatic and unconscious, activate different encoding processes that produce differential recognition abilities between ownand other-race faces (Meissner, Brigham, & Butz, 2005). The CRE has received a lot of attention partly because it advances the understanding of the different mechanisms that people use to process faces (Arizpe, Kravitz, Walsh, Yovel, & Baker, 2016). It is also important in the field of criminal justice because it exposes the challenges associated with eyewitness identification during lineups—especially when the eyewitness and the suspect are from different races (Lindsay, Mansour, Bertrand, Kalmet, & Melsom, 2011). The literature shows that the CRE has been explained through different mechanisms which include a perceptual narrowing due to experience (Kelly et al., 2009), failure to generalize perceptual encodings (Levin, 2000), differences between holistic and featural processing (Tanaka, Kiefer, & Bukach, 2004), social-cognitive processes of categorization (Shriver, Young, Hugenberg, Bernstein, & Lanter, 2008), among others. The CRE has proven to be a complex phenomenon that is affected by many variables, a process that is reliable, but challenging to study because its effects are dependent upon the different experimental paradigms and method of CROSS-RACE EFFECT, EYE-TRACKING AND SOCIAL BACKGROUND 4 analysis that are used. However, despite its convoluted nature, the CRE has been detected as early as in the first few months of life. Indeed, Kelly et al. (2009) documented the evolution of the CRE in Asian babies. The authors demonstrated that a) 3-month-old Asian babies recognize Asian, Caucasian, and African faces, b) that six-month-old Asian babies recognize Asian faces, are able to perform marginal recognition of Caucasian faces, and are not able to recognize African faces, and c) that 9-monthold Asian babies only recognize Asian faces. The authors concluded that the CRE supports the perceptual narrowing hypothesis, which argues that during the developmental process, the brain uses the stimuli that are most commonly encountered in the environment to shape and fine-tune the perceptual systems (Hadley, Rost, Fava, & Scott, 2014). In this way, just as the auditory system rapidly adapts to perceive the phonetic properties of the particular language that is spoken around babies, the visual system performs a similar feat by becoming more sensitive to the facial features that are more commonly seen. Furthermore, a study done in kindergarten, 3rd graders and young adults showed that the CRE remains present and stable as individuals grow up (Pezdek, Blandon-Gitlin, & Moore, 2003). However, just as with language, the face recognition system seems to remain plastic during the first years of life as it adapts to changes in the social environment of individuals. For instance, Korean children who were adopted when they were between three and nine years old, and who moved out of Korea to be raised in Europe by Caucasian families, showed a cross-race effect while looking at Korean faces when they were tested in adolescence—lowered ability to remember Korean faces compared to Caucasian faces (Sangrigoli, Pallier, Argenti, Ventureyra, & Schonen, 2005). This study shows how expertise gained with cross-race faces can reduce or even revert the cross-race effect. CROSS-RACE EFFECT, EYE-TRACKING AND SOCIAL BACKGROUND 5 The mechanisms underlying the CRE are heavily debated in the literature. Some authors suggest that the effect is the result of a failure to generalize the perceptual mechanisms that are used for same-race encoding, and to effectively use these mechanisms to process cross-race faces (Levin, 2000). The deficit is believed to be the result of the subconscious and automatic act of emphasizing race information when processing cross-race faces at the expense of performing an individuation of facial features. Correll, Hudson, Guillermo, and Earls (2016) suggest that differential experience with in-group faces promotes a higher perceptual enrichment for these faces, thus allowing people to create richer and better integrated mental representations of samerace faces. According to this, same-race faces are normative, and through top-down processes, race not only structures the social environment, but also structures mental representations, influences visual processing, perceptual learning, and predictive coding. Indeed, a study that considered this hypothesis found a significant effect when participants were asked to individuate the information of cross-race faces, as opposed to just categorize faces by race (Rhodes, Locke, Ewing, & Evangelista, 2009). The authors concluded that the poor recognition of faces of other races could also be the result of a process that starts with a reduced perceptual expertise of other-race faces in addition to a reduced motivation to individuate out-group faces. Additionally, other authors have noted that incremental experience helps people to better differentiate both individual facial features and the spatial relationships between these features, thus leading to a reduced CRE (Maurer, Le Grand, & Mondloch, 2002). Further studies suggest that holistic processing of faces increase the CRE as a result of a high familiarity with same-race faces (Tanaka et al., 2004). Researchers Tanaka and Farah (1993) describe holistic processing as a mechanism by which the encoding process of facial features is based on the information of the spatial relationships between all the main features of CROSS-RACE EFFECT, EYE-TRACKING AND SOCIAL BACKGROUND 6 the face. Tanaka et al. (2004) report a direct correlation between holistic processing and the relative experience of the subjects with ownand cross-race faces, with Caucasians showing more holistic processing when viewing own-race faces. However, holistic processing does not seem to be a universal processing mode for own-race faces as the authors also found that Asians rely on holistic processing when viewing both Asian and Caucasian faces. Hayward, Crookes and Rhodes (2013) explain holistic coding as the ability of an individual to process the configural information of a face by processing the distances between all the main features of the face, thus creating an exemplar that is stored as a deviation from the typical dimensions of a referential face. The referential face is a statistical construct stored in the brain which has been created by the countless times that an individual has come across the faces of a particular race. The holistic processing is deemed functionally advantageous because it is effortless and automatic as it allows the observer to a) process all the configural relationships between all the face features at the same time, b) compare the spatial ratios of the face being viewed with a referential face of the same race, and c) consciously detect, if necessary, what differentiates the face from the norm. Conversely, during featural processing, the observer processes facial characteristics relatively independently, paying attention to distinctive features and tagging the face with mental notes that help in later recognition, as for example: mole on left cheek, small ears, square-shaped face, etc. Hummel and Biederman (1992) report that featural processing seems to be the standard process used by humans to process objects in the world. However, Hayward et al. (2013) notes that featural processing is less useful in faces because all the exemplars are composed of the same elements (eyes, nose, mouth), thus the tendency of the brain to process faces using the pattern recognition analysis particular of holistic coding. Yet, for the brain to be able to use CROSS-RACE EFFECT, EYE-TRACKING AND SOCIAL BACKGROUND 7 holistic processing, a person needs to have significant experience leading to the brain mapping of a referential face for a particular race. Further, when Hayward et al. (2013) reviewed previous studies where researchers manipulated configural and featural components of the target faces, they found that Caucasian and Asian participants still perform better with own-race faces when forced by the experiment to use featural processing. The authors concluded that improved encoding of own-race faces is not necessarily tied to holistic