Study 4 —Picture Rather Than Face Recognition?

Our results so far have consistently failed to support a social-motivational origin of the other-race effect in our participants, when our face recognition tasks have used a demanding format — the CFMT — that mimics real-world requirements by asking

allowing participants to use changeable non-face cues such as hairstyle or clothing. These results contrast with previous motivation-to-individuate studies where results support a social-motivation contribution to the ORE (i.e., improved other-race face recognition and reduced ORE; G. Rhodes et al., 2009; Hugenberg et al., 2007; Young et al., 2010; Young & Hugenberg, 2012). In Study 4 we test whether the difference in results could be attributable to the fact that those studies used a 'same-image' face memory task (i.e., picture of a given face in the memory test phase is identical to the picture learned at study). To do so, we changed our task to a same-image recognition task and modelled the procedure and the appearance of the face pictures as closely as possible on that used by Hugenberg et al., 2007 (and also Young et al., 2010 and Young & Hugenberg, 2012).

3.6.5  Method

3.6.5.1  Design

We used a 2 × 2 × 2 mixed design, with within-subjects factor race-of-faces (CFMT-Australian face task vs CFMT-Chinese face task) and between-subjects factors instruction condition (No Instruction vs Motivation Instruction), and race-of-observer (Western-raised Caucasian group vs Eastern-raised Asian group). For the face-picture recognition task (Figure 2), participants learned 40 faces one at a time (20 Caucasian faces and 20 Asian faces, intermixed as in the Hugenberg procedure rather than blocked as in our Study 1), then at test performed old-new decision on 80 faces (40 of each race; half learned at study and referred to as the 'old' faces, half new distractors). The primary dependent measure was accuracy of the recognition decision (calculated as d'); we also recorded reaction time.

3.6.5.2  Participants

For the Western-raised Caucasian group (n = 198; 55 male, 140 female, 3 circled "other" as gender; mean age = 21.2 years, SD = 3.6, range 17-45 years), 106 were given No Instructions and 92 were given Motivation Instructions. For the Eastern-

raised Asian group (n = 181; 55 male, 126 female; mean age = 22.0 years, SD = 2.8,

range 17-33 years; mean length of time living in the West = 18.3 months, SD = 16.8, range = 1-77 months), 92 were given No Instructions and 89 were given Motivation

Instructions. Participants met the same criteria for group membership as in Study 1. Most participants (86%) were the same as those analysed for Study 1 (see

Supplementary Materials Table S1 for details). Additional participants needed to top up numbers in each race and each motivation condition for the face-picture task were tested individually.

3.6.5.3  Instructions

Instructions for the No Instructions and Motivation-to-individuate condition were as for Study 1 (for exact wording see Supplementary Materials Appendix 1). Note that a given participant remained in the same instruction condition throughout all the face tasks s/he completed (i.e., Study 1 tasks and Study 4 tasks).

3.6.5.4  Face-picture task: Stimuli

Figure 2 shows examples of our stimuli. In order to ensure a close match to Hugenberg et al. (2007; also note their stimulus set was re-used in Young et al., 2010, and Young & Hugenberg, 2012), we used the same number of faces (40 of each race), all the faces were male with neutral expressions in frontal view, the images were in greyscale, the images included the hair not just the face (and also a small amount of collar on some images), and the same photograph of each person was used at learning and test. Face images averaged 5.7° vertical visual angle (6 cm tall viewed at 60 cm).

Our Caucasian face images were taken from the Radboud Faces Database (Langner et al., 2010) and The Karolinska Directed Emotional Faces (KDEF)

(Lundqvist, Flykt, & Ӧhman, 1998). Our Asian face images, showing people of Chinese ancestry, were taken from the Chinese University of Hong Kong Face Sketch database (CUFS) (Wang & Tang, 2009).

3.6.5.5  Face-picture task: Procedure and scoring

The following aspects of our procedure were identical to that reported by

Hugenberg et al. (2007). At learning: the learning phase presented 20 faces of each race (40 'old' faces total); the two races of face were intermixed; and each face appeared one a time in the center of the screen for 2s. In the memory test phase: participants were

of the 80 test pictures (20 learned Caucasian faces, 20 learned Asian faces, 20 new Caucasian faces, 20 new Asian faces) was displayed one at a time; the two races of face were intermixed; each face appeared in the centre of the screen and remained visible until participants responded by key press to indicate whether they judged the face to be old (learned) or new (not learned). There were three minor differences from the

procedure of Hugenberg et al. (2007). First, we included no break between the learning and test stages (pilot testing revealed that including this delay placed memory for our face items too close to floor). Second, we used the same pseudorandom order of trials for all participants (with constraints that no more than three trials in a row showed the same race of face, and the mean and SD of position-in-the list were closely matched at study for Asian and Caucasian faces, and at test for Old Asian, New Asian, Old Caucasian and New Caucasian faces), rather than using a different random order for every participant. Third, we used the same set of 40 faces as the learned faces for all participants, rather than counterbalancing face items across learned and new conditions across participants (this was done because counterbalancing in the lab-class testing situation was not feasible while also counterbalancing other, more important, factors such as CFMT-task order; see Study 1). None of these minor differences from Hugenberg et al.'s procedure would be expected to influence the ORE or motivation effects on the ORE in any way.

Scoring. In calculating d', we replaced Hit rates of 1 with 1 - 1/(2N), where N = 20 (N = the number of targets) and False Alarm rates of 0 with 1/(2N), where N=20 (N = the number of lures; Green & Swets, 1966). Hits and False Alarms are reported

separately in Supplementary Materials, Table S4. For reaction time, we calculated mean reaction time for each participant, excluding trials where the response was incorrect, or the response time was pre-emptive (RT faster than 300ms) or an outlier (slower than mean+2.5SDs of correct-response RTs separately for the faces of each race).

3.6.6  Results

3.6.6.1  Matching of stimulus set difficulty

Our Caucasian and Asian face stimulus sets for the same-images task were matched for intrinsic difficulty, as shown by comparing the two sets for own-race performance in the 'standard' no instructions condition. There was no difference between Caucasian-participant performance on the Caucasian faces and Asian-

participant performance on the Asian faces, on either accuracy (Mean d' = 1.28 vs 1.24 respectively, t(196) = 0.377, p = .707), or reaction time (1349ms vs 1396ms, t(196) = 0.679, p = .498). Thus, as with the CFMT tasks, the ORE can be validly measured even within a single observer group.

3.6.6.2  Other-race effect on memory: Accuracy (d')

We report memory accuracy calculated as old-new discrimination, using d' as did Hugenberg et al. (2007). Results (Figure 6) again show no support for the

predictions of the social-motivation theory: despite changing to a same-images task to match the method of previous studies, we found no evidence that the motivation-to- individuate instructions reduced the ORE in our participants. A 3-way ANOVA revealed a highly significant other-race effect, namely a crossover interaction between race-of-face and race-of-observer that reflected poorer memory (lower d') for other-race faces (inside bars in each plot of Figure 6) than own-race faces (outside bars), F(1,375) = 61.751, MSE = 12.713, p < .001. There was no 3-way interaction between race-of- face, race-of-observer and instructions condition, F(1, 375) = 0.482, MSE = .099, p

= .488, indicating that motivation instructions did not significantly alter the size of the other-race effect. A priori analysis of each instruction condition separately showed

**"="p<.01" ""*"="p<.05" A.#No#instruc-on# B.#Mo-va-on2to2individuate# Face#memory#with#same#images#at#learning#and#test#(face2picture#task)# Ac cu ra cy #(d’) # ORE=0.26**" ORE=0.21**" ORE=0.29**" ORE=0.28**" O w n2 rac e" O w n2 rac e" O th er 2r ac e" O th er 2r ac e" Caucasian"faces" Asian"faces" Face"s@muli:" O w n2 rac e" O w n2 rac e" O th er 2r ac e" O th er 2r ac e" 0.3" 0.5" 0.7" 0.9" 1.3" 1.1" 1.5" ORE=213ms" ORE=115ms**" ORE=35ms" ORE=268ms" Western2raised""

Caucasians"(n=106)" Eastern2raised""Asians"(n=92)"

O w n2 rac e" O w n2 rac e" O th er 2r ac e" O th er 2r ac e" Western2raised""

Caucasians"(n=92)" Eastern2raised""Asians"(n=89)"

Par-cipants# Par-cipants# 0.8" 1.0" 1.2" 1.4" 1.8" Re ac -o n# Ti m e# (s )# _1.6" O w n2 rac e" O w n2 rac e" O th er 2r ac e" O th er 2r ac e"

Figure 6. Study 4 results: mean face-picture memory accuracy (d’; chance = 0) and reaction times with (A) no instructions, and (B) motivation instructions. Format as for Figure 4.

instruction condition, F(1, 196) = 34.538, MSE = 7.863, p < .001, and in the motivation condition, F(1,179) = 27.843, MSE = 5.068, p < .001. Considering each race of

participant separately, for Caucasian observers memory was significantly better for own-race faces (Caucasian images) than other-race faces (Asian images), both with no instructions, t(105) = 4.277, p < .001, and with motivation instructions, t(91) = 3.604, p

= .001, and the size of the other-race effect (Caucasian minus Asian images) was not significantly smaller in the motivation condition (0.21) than with no instructions (0.29),

t(196) = 0.823, p = .411. For Asian observers, memory was significantly better for own-race faces (Asian images) than other-race faces (Caucasian images), both with no instructions, t(91) = 4.063, p < .001, and with motivation instructions, t(88) = 3.845, p

< .001, and the size of the other-race effect (Asian minus Caucasian images) was not significantly smaller in the motivation condition (0.26) than with no instructions (0.28),

t(179) = 0.181, p = .857. Finally, we tested the social-motivation prediction that

motivation-instruction effects should specifically improve memory for other-race faces. There was no support for this prediction. For Caucasian observers, motivation

instructions did not improve memory for Asian faces (no motivation d' M = 0.99; motivation M = 0.98, t(196) = 0.096, p = .924) and, for Asian observers, motivation instructions did not significantly improve memory for Caucasian faces (no motivation

M = 0.96; motivation M = 1.00, t(179) = 0.433, p = .666).

3.6.6.3  Other-race effect on memory: Reaction time

The Hugenberg studies (and that of G. Rhodes et al., 2009) did not report RTs but we present them in Figure 6 for completeness. Again, motivation instructions did not reduce the size of the ORE: indeed, RTs showed no significant ORE in either instruction condition (no race-of-face × race-of-observer interactions without

instructions, p > .4, or with motivation instructions, p = .083) and no significant change across conditions (no 3-way interaction between race-of-face × race-of-observer x instructions, p > .1).

3.6.6.4  Did the motivation instructions have any effects at all on memory behaviour?

As for the CFMT, motivation instructions produced the same trends towards longer overall RTs — indirectly suggestive of more effort — in the motivation condition than the no instructions condition (see Figure 6), although these trends only

approached significance: overall, main effect of instructions in 3-way ANOVA, F(1, 375) = 2.935, MSE = 969604.660, p = .087; Asian observers, F(1,179) = 3.353, MSE = 1354467.442, p = .069.

3.6.7  Discussion

Study 4 shows that the difference between our results and those of previous studies that supported social-motivational theories cannot be attributed to the use of different types of memory tasks; namely, the use of same- versus novel-images of the learned faces. We have found the other-race effect was present, and unaffected by motivation-to-individuate instructions, on both same-images memory tasks (Study 4) and on memory tasks that require recognition of a person over lighting and viewpoint change (Study 1).

Again, we emphasise that our lack of motivation instruction effect cannot be attributed to any obvious methodological problems. As in Study 1, we have large sample sizes and small error bars (Figure 6), meaning there is unlikely to be a power problem. In addition, memory performance again did not suffer from floor or ceiling effects (Figure 6); indeed, the overall d' for the Caucasian participants in the present study is almost exactly the same as it was for Caucasian participants in Hugenberg et al. (2007). Also note the signal detection analysis revealed the same pattern of old-new decision bias in our Caucasian participants as Hugenberg et al (2007) found in their Caucasians (specifically, a tendency to see other-race faces as "old" rather than "new"; for data see Supplementary Materials, Table S4).