Current Biology, Volume 19

Supplemental Data
Cultural Confusions Show that
Facial Expressions Are Not Universal
Rachael E. Jack, Caroline Blais, Christoph Scheepers, Philippe G. Schyns, and Roberto Caldara

Supplemental Experimental Procedures
Subject Questionnaire
Each potential observer completed the following questionnaire. We selected only thoseanswering ‘no’ to all questions for participation in the experiment.
Have you ever:a) lived in an other-race country (e.g., on a gap year, summer work, move due parentalemployment)b) visited an other-race country (e.g., vacation)c) dated interraciallyd) had close other-race friendshipse) been involved with any other-race societies (e.g., university cultural societies)

Table S1. Categorization Accuracy for Western Caucasian (WC) and East Asian (EA)
Observers across All Facial Expressions and Same Race (SR) and Other Race (OR)Face Stimuli*p < 0.05; **p < 0.001.

Figure S1. Confusion Matrices of Categorization Errors for Western Caucasian (WC) andEast Asian (EA) Observers for Same Race (SR) and Other Race (OR) Faces
The color-coded confusion matrices show the number and type of expression mis-categorizations
made by WC and EA observers for SR and OR faces. The rows of each matrix correspond to thestimulus expression presented and the columns correspond to the response given by observers (N= ‘neutral’, H = ‘happy’, Su = ‘surprise’, F = ‘fear’, D = ‘disgust’, A = ‘anger’, and S =‘sadness’).

Figures S2–S6. Eye Movement Analysis Conducted across All Conditions of theExperiment (7 Expressions and 2 Races of Face) for Western Caucasian (WC) and East
Asian (EA) Observers

Figure S2. Fixation Distributions for Each ConditionColor-coded distributions presented on gray-scale sample stimuli show the relative distributionsof fixations across Face regions. Color-coding is as follows: blue – ‘left eye’, green – ‘right eye’,yellow – ‘bridge of nose’, orange – ‘center of face’, red – ‘mouth’. Higher color saturation
indicates higher fixation density, shown relative to all conditions. Note that the red ‘mouth’
fixations for EA observers are less intense compared to WC observers across all conditions,including ‘happy’. Color-coded bars represent the mean accuracies for each condition where redindicates a significant difference in categorization errors between observer groups (p < 0.05).
Error bars indicate standard errors of the mean.

Figure S3. Minimum Description Length (MDL) – Group Analysis
Fixation sequences for each condition. Successions of color-coded circles represent the fixation
sequences extracted using Minimum Description Length (MDL) analysis with each circle
representing a Face region. Face regions are color-coded as follows: blue – ‘left eye’, green –‘right eye’, yellow – ‘bridge of nose’, orange – ‘center of face’, red – ‘mouth’. For example, thesuccession of blue - green - blue circles (indicated with a black arrow) corresponds to thefixation sequence ‘left eye’ - ‘right eye’ - ‘left eye’. Black and white bars to the right of the
fixation sequences represent how frequently the fixation sequence appeared in the data set, withblack indicating correct trials and white indicating incorrect trials. Different levels of gray ineach condition represent the order of the fixation sequences (see Experimental Procedures). Notethe higher number of fixations sequences for EA observers compared to WC observers across allconditions. Color-coded bars represent the mean accuracies for each condition where redindicates a significant difference in categorization errors between observer groups (p < 0.05).
Error bars indicate standard errors of the mean.

Figure S4. Minimum Description Length (MDL) – Individual Analysis
Fixation sequences common across individual observers. To isolate the fixation sequences usedby individuals within each observer group, we conducted MDL analysis (see ExperimentalProcedures) on each individual observer data set separately. Successions of color-coded circles
represent the fixation sequences extracted using Minimum Description Length (MDL) analysis.
Each circle represents a face region and are color-coded as follows: blue – ‘left eye’, green –‘right eye’, yellow – ‘bridge of the nose’, orange – ‘center of face’, red – ‘mouth’, as depicted in
the face above. Black bars appearing to the right of each fixation sequence represent the numberof observers using the fixation sequence. Note (1) the higher number of fixation sequences for
EA observers compared to WC observers and (2) the more systematic and repetitive use of theeyes for EA observers (i.e. green-blue sequences) compared to WC observers who sample theeyes and mouth equally. This confirms that the persisting fixation sequences to the eyes reported
for the EA group of observers was present in a majority of individual observers.

Figure S5. Model Observer Sampling Method
Illustration of the procedure to compute estimated patterns of confusion.
(A) Information samples. To compute estimated patterns of confusion, the model sampled face
information from the stimulus expression (e.g., ‘fear’) and from the same location on the otherexpressions (e.g., ‘surprise’, ‘anger’, ‘disgust’, ‘sadness’, and ‘neutral’). The face images
illustrate an example of the information sampled.
(B) Confusion patterns. The model then Pearson correlated the stimulus expression sample witheach of the other expression samples. These correlations (plotted in dashed color-coded lines
beneath each corresponding face) represented the confusions of the model and were fitted (in aleast means squared sense) against the behavioral confusions of the EA observers (plotted inblack). The behavioral confusions of the EA observers were obtained by categorizing eachincorrect trial by response, for each expression (e.g., for ‘fear’ trials, the number of incorrect
responses were computed for ‘neutral’, ‘surprise’, ‘disgust’, ‘anger’, and ‘sadness’). We repeatedthe sampling and correlation process for 10,000 individual samples selected randomly across theface and finally sorted each information sample according to its fit to the behavioral confusionsof the EA observers (‘best’ to ‘worst’ fits are shown in Figure S6). We followed the sameprocedure for each expression.

Figure S6. Model Observer and East Asian Observer Fixation Maps
Contour Plots: Color-coded lines represent the rank order of information samples according tofit, with red showing the ‘best’ fit (scale on left).
Fixation Patterns: For each expression, fixations leading to behavioral confusion errors areshown by relative distributions presented on gray-scale sample stimuli. Red areas indicate higher
fixation density for each expression (scale on right). Note the higher density of EA observer
fixations within face regions ranked as ‘best fit’ across all expressions, demonstrating that thebehavioral confusions of EA observers are due to an information sampling strategy that selects
ambiguous information (i.e. the eyes and eyebrows) while neglecting more diagnostic features(i.e. the mouth).