Supplementary Online Material:
Beyond face value: Evidence for the universality of bodily expressions of emotion
Zachary Witkower1 Alexander K. Hill2
Jeremy Koster3 Jessica L. Tracy1
University of British Columbia1 University of Washington2
University of Cincinnati3
Please Address Correspondence to:
Zachary Witkower
University of British Columbia 2136 West Mall
Vancouver, BC Canada V6T 1Z4 Zak.Witkower@psych.ubc.ca
Validation of bodily expression stimuli
Participants
One hundred fifty American participants were recruited from Amazon Mechanical Turk.
Ten of these participants failed an attention check question (see Witkower, Tracy, Cheng, &
Henrich, 2020), yielding a final sample of 143 participants (67% male, M age = 34.87 years, SD
= 9.98, 79% White/Caucasian).
Materials
Two targets (1 male, 1 female) posing bodily expressions of anger, sadness, fear, and neutral were selected from the Bodily Expressive Action Stimulus Test (BEAST; De Gelder &
Van den Stock, 2011). The BEAST is comprised of whole-body expressions of anger, fear, sadness, neutral, and happiness, with the face of each actor blurred and bodies fully visible.
Procedure
Participants were shown the same eight trials that were presented to Mayangna
participants, in a random order, and in each trial selected the image that best corresponded to a given prompt. Prompts were English versions of those used with the Mayangna participants, except that for the neutral expression, M-Turk participants were asked to “select the image in which the person is neutral”, instead of “the image in which the person is neither happy nor sad.”
Results
In line with our primary analyses, we analyzed recognition rates collapsing across participant and target sex. Recognition rates were significantly greater than chance for all expressions: 93% for sadness (95% CI: [89% to 96%], p < .001), 94% for anger (95% CI: [90%
to 96%], 92% for neutral (95% CI: [88% to 95%], p < .001), and 94% for fear (95% CI: [91% to 97%], p < .001; see Figure S1).
Figure S1. Mean recognition rates for each emotion expression among American MTurk participants. The dotted line indicates chance guessing (25%). Error bars represent 95%
binomial confidence intervals.
Additional information about the Mayangna sample
All members of the Mayangna community were recruited for the present research during an introductory meeting to explain the general goals of the study (“we are interested to know how Mayangna/Miskito perceive others”), the length of the procedure, details about
compensation, and logistics for signing up to participate. Introductory information, along with English and Spanish study materials, can be obtained by contacting the first author. Participants were reminded that their participation was completely voluntary. The study was conducted over a roughly 3-week period in January 2018, during which interviews were conducted in multiple private locations around the community, often in the interviewees’ homes. Author AH and his assistant interviewed more than approximately 90% of the adult members of the community, and all interviewees received the equivalent of $2.00 USD in Nicaraguan Córdobas for their
participation.
Mayangna individuals subsist mainly on foods harvested from their agricultural plots, as well as harvested fish and hunted game (Sznycer et al., 2018). Community members raise a variety of crops – horticulture practices provide rice, beans, bananas and manioc. Many individuals also keep livestock including fowl, pigs, and cows (Sznycer et al., 2018, Koster, 2018). Residents are able to earn some money by selling cash crops or animals, or they rely on gold panning – an activity pursued by both men and women (Koster, 2018). A limited number of teaching positions are available in the community school – these salaried positions are held mostly by males. Overall, wealth inequality in the community is relatively high, as indicated by a Gini coefficient of 0.55 for household wealth (Koster, 2018).
The sexual division of labor follows historical trends seen in Western societies but is much sharper than that familiar to North Americans. Men are largely responsible for money-
earning activities, heavy labor in the field, and hunting and fishing (Koster, 2018, Winking, Eastwick, Smith, & Koster, 2018). Women take care of most domestic tasks, such as food processing, sewing, and child care (Koster, Grote, & Winterhalder, 2013). Fertility is early (mean age at first birth is approximately 17 years for women) and high (fertility rate exceeds seven births per woman; Koster, 2018, Winking et al., 2018). These factors, along with cultural norms and husbands' jealousies, often limit women's opportunities outside the home. However, these labor distinctions are not absolute—for instance, men and women collaborate in
agricultural labor, and fathers often tend to and play with children (Winking et al., 2018; Koster, Grote, & Winterhalder, 2013)
Results separated by target and participant sex Full sample
Recognition rates for sadness, anger, and fear expressions did not vary by target sex, χ2s
< 2.15, ps > .18. In contrast, neutral expressions were better recognized when displayed by the female target, χ2(1) = 12.03, p = .001, but for both the male (42%) and female (65%) target, these rates were significantly greater than chance (ps < .001; see Table S1). Recognition rates did not vary by participant sex, and this held for all four expressions, χ2s < 2.15, ps > .18; see Table S2).
Table S1. Mayangna participants’ accurate selection rates for each emotion expression, separated by target sex, along with chi-squared test of equal proportions for target sex.
Emotion
Expression Male target
recognition rate Female target
recognition rate χ2 df p
Sadness 89% 82% 1.78 1 .18
Anger 71% 74% 0.65 1 .65
Fear 52% 42% 2.15 1 .14
Neutral 42% 65% 12.03 1 .001
Table S2. Mayangna participants’ accurate selection rates for each emotion expression, separated by participant sex, along with chi-squared test of equal proportions for participant sex.
Emotion Expression
Male participants’
recognition rate
Female participants’
recognition rate
χ2 df p
Sadness 85% 86% <0.01 1 .98
Anger 70% 75% 0.40 1 .52
Fear 50% 44% 0.51 1 .48
Neutral 54% 53% <0.01 1 >.99
Highly isolated subsample
Within this sample, recognition of sadness, anger, and fear expressions did not vary by target sex, χ2s < 0.61, ps > .43. However, the neutral expression was better recognized when shown by the female than the male target, χ2(1) = 5.40, p = .02; the female target’s neutral expression was recognized at a rate significantly greater than chance (67%, 95%CI: [47% to
83%], p <.001), but the male target’s was not (33%, 95%CI: [17% to 53%], p = .29).
Recognition rates for all four expressions did not vary by participant sex, χ2s < 0.79, ps > .38.
Unbiased hit rates
Table S3. Selections made by participants in the full sample, along with unbiased hit rates (Hu).
Nonverbal display selected: Hu
Prompt Sad Anger Fear Neutral
Sad 194 2 5 25 50%***
Anger 8 164 38 16 57%***
Fear 91 8 106 21 28%***
Neutral 38 36 31 121 35%***
Note: Accurate selections in bold. Unbiased hit rates (Hu) and significance tests are calculated as outlined by Wagner (1994).
*** p< .001; ** p< .01; * p< .05.
Table S4. Selections made by participants in the highly isolated subsample, along with unbiased hit rates (Hu).
Nonverbal display selected: Hu
Prompt Sad Anger Fear Neutral
Sad 46 2 1 11 42%***
Anger 4 39 13 4 45%***
Fear 26 2 26 6 23%***
Neutral 10 13 7 30 30%***
Note: Accurate selections in bold. Unbiased hit rates (Hu) and significance tests are calculated as outlined by Wagner (1994).
*** p< .001; ** p< .01; * p< .05.
Translation Procedures
All materials were translated from English to Spanish, then back-translated from Spanish to English, prior to the study, and then translated from Spanish to the Mayangna and Miskito languages on-site by J.K. and two research assistants fluent in Spanish, Mayangna, and Miskito (for all original materials in English, Spanish translations of those materials, and Spanish-to- English back-translations, see osf.io/tg3fe). Table S4 shows translations for emotion-word prompts.
Table S4. Initial English prompts, Spanish translations, and English back- translations used in the current study.
Condition
English prompt
Spanish translation
English back-translation Neutral "Calm" "Tranquilla" "Relaxed"
Sad "Sad" "Triste" "Sad"
Afraid "Afraid" "Miedo" "Afraid"
Angry "Angry" "Enojada" "Angry"
References
De Gelder, B., & Van den Stock, J. (2011). The bodily expressive action stimulus test
(BEAST). Construction and validation of a stimulus basis for measuring perception of whole body expression of emotions. Frontiers in psychology, 2, 181.
Koster, J. (2018). Family ties: the multilevel effects of households and kinship on the networks of individuals. Royal Society Open Science, 5(4), 172159.
Koster, J. M., Grote, M. N., & Winterhalder, B. (2013). Effects on household labor of
temporary out-migration by male household heads in Nicaragua and Peru: an analysis of spot-check time allocation data using mixed-effects models. Human Ecology, 41(2), 221-237.
Sznycer, D., Xygalatas, D., Alami, S., An, X. F., Ananyeva, K. I., Fukushima, S., ... &
Onyishi, I. E. (2018). Invariances in the architecture of pride across small-scale societies. Proceedings of the National Academy of Sciences, 115(33), 8322-8327.
Winking, J., Eastwick, P. W., Smith, L. K., & Koster, J. (2018). Applicability of the
Investment Model Scale in a natural‐fertility population. Personal Relationships, 25(4), 497-516.
Witkower, Z., Tracy, J. L., Cheng, J. T., & Henrich, J. (2020). Two signals of social rank:
Prestige and dominance are associated with distinct nonverbal displays. Journal of Personality and Social Psychology, 118(1), 89-135.
