LETTER

Reply to Sauter and Eisner:
Differences outweigh commonalities
in the communication of emotions
across human cultures
In response to our work (1), Sauter and Eisner (2) argue,“. . . [our] strong claims . . . are not supported by [our] data.”
Herein, we show that their arguments are unsubstantiated,primarily reﬂecting misunderstandings.
Sauter and Eisner argue “. . .[EA] understanding of English
emotion terms ... may have been more variable . . . becauseof varying lexical correspondence . . . as well as . . . English
proﬁciency.”
East Asian (EA) observers possessed a minimum International English Language Testing System score of 6.0(1, p. 2), including use of fairly complex language. As highfrequency words, all emotion labels were also well withincapability. Furthermore, before testing, we established comprehension by obtaining descriptions and synonyms of eachemotion label.
Sauter and Eisner argue “Because the Chinese ‘cultural group’includes many cultural and linguistic subgroups, variability evenfor in-group signals should be expected.”
We show variance primarily between emotion categories,
refuting the notion that both cultures represent each basic
emotion with the same set of facial movements. If variability
arose because of linguistic difference in subcultures (and whereuniversality is supported) one would expect variance only withinemotion categories.
Sauter and Eisner argue “. . . [Jack et al.,] found an optimal solution with fewer than six clusters in the East Asian (EA) group. . .”Our analysis demonstrates an optimal ﬁt of six clusters forWestern Caucasian (WC) only. No optimal ﬁt exists for EA,
regardless of cluster number. In fact, Fig. S1 in ref. 1 explicitlyreveals that EA Mutual Information never reaches a levelcomparable to WC, because of overlap in facial movements
between basic emotion categories.
Sauter and Eisner argue “. . .[our methods] fail to account for [conﬁgural facial expression processing]. . .
and . . .dynamic cues.”
Our methods captured the dynamic face information signiﬁcantly associated with the cultural perception of eachemotion (ﬁgure 1 in ref. 1). In fact, in Movie S2 in ref. 1, theEA “happy” model displays synchronous upwards eyebrow
motions before the mouth (Fig. 1 here shows corresponding
temporal curves). Our methods do capture relevant dynamic
information, including order, speed, and synchrony of facial
conﬁgurations.
Sauter and Eisner argue “. . . [dynamic reverse correlation]
method is imperfect even in the ‘baseline’ case of Caucasian
Europeans.”

www.pnas.org/cgi/doi/10.1073/pnas.1211865110

Fig. 1. Dynamics of an East Asian “happy” model (see Movie S2 in ref. 1 for
optimal understanding). Color-coded curves represent the temporal dynamicsof the Action Units (AUs) signiﬁcantly correlated with the perception of“happy” in an East Asian observer. High Intensity (Movie S2, right column):
AU2 (outer brow raiser, dark blue curve) has an earlier onset relative to theother AUs (Movie S2 shows early eyebrow ﬂick), demonstrating speciﬁcordering of AUs. In contrast, the other AUs are more synchronous, as illustrated
by similar temporal curves. Low Intensity (Movie S2, left column): AU synchrony
is further demonstrated. Thus, our methods do capture a variety of temporal
differences in the mental representations of facial expressions of emotion[see also Fig. 3 in our work (1) for culture-speciﬁc spatiotemporal locationsof emotional intensity representation in different facial expressions].

Sauter and Eisner (2) base their argument on different
research (3) reporting aggregate normalized correlations
between WC model facial movements and proposed prototypes and variants (4). Their statement is unwarranted forthree reasons.
First, each aggregate correlation was statistically signiﬁcant,demonstrating a close ﬁt of our WC models to “baseline.”
Maximum-ﬁt analysis revealed perfect and near-perfect ﬁts forall six expressions.
Second, although proposed prototypes and variants
describe different ways of expressing the same emotion (e.g.,“surprise” with open or closed mouth), their natural variance(i.e., how each is distributed within/between cultures) is
unknown. Our data-driven methods, which harness subjective
cultural perceptions, do capture the natural variance of facial

Author contributions: R.E.J., O.G.B.G., H.Y., R.C., and P.G.S. designed research; R.E.J., O.G.B.G.,and H.Y. performed research; P.G.S. contributed new reagents/analytic tools; O.G.B.G.
analyzed data; and R.E.J. and P.G.S. wrote the paper.
The authors declare no conﬂict of interest.
1To whom correspondence should be addressed. E-mail: rachael.jack@glasgow.ac.uk.

PNAS | January 15, 2013 | vol. 110 | no. 3 | E181–E182

expressions, including a spectrum broader than those currently
proposed (e.g., happy with parted lips).
Third, the models are recognized with a high accuracy comparable
to those reported with standardized 2D faces (e.g., refs. 5 and 6).
Thus, existing facts demonstrate that our methods can expand
current knowledge beyond basic facial expressions, revealing
natural variance within a culture.
Rachael E. Jacka,b,1, Oliver G. B. Garrodb, Hui Yub, Roberto Caldarac,and Philippe G. SchynsbaSchool of Psychology and bInstitute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, Scotland; andE182 | www.pnas.org/cgi/doi/10.1073/pnas.1211865110

cDepartment of Psychology, University of Fribourg, Fribourg 1700,
Switzerland

1. Jack RE, Garrod OGB, Yu H, Caldara R, Schyns PG (2012) Facial expressions of emotion
are not culturally universal. Proc Natl Acad Sci USA 109(19):7241–7244.
2. Sauter D, Eisner F (2012) Commonalities outweigh differences in the communication of emotions across human cultures. Proc Natl Acad Sci USA 110:E180.
3. Yu H, Garrod OGB, Schyns PG (2012) Perception-driven facial expression synthesis.
Comput Graph 36:152–162.
4. Ekman P, Friesen WV (1978) Facial Action Coding System: A Technique For The
Measurement Of Facial Movement (Consulting Psychologists Press, Palo Alto, CA).
5. Jack RE, Blais C, Scheepers C, Schyns PG, Caldara R (2009) Cultural confusions showthat facial expressions are not universal. Curr Biol 19(18):1543–1548.
6. Nelson N, Russell JA Universality revisited. Emotion Review, 10.1177/1754073912457227.

Jack et al.