Most emotion perception assessments were developed in western societies using English terms and Caucasian faces, so the extent to which they are cross-culturally valid is in question. To sort this, understanding the mechanisms of cultural variations is the key. In the past half-century, cross-cultural differences in perceiving facial emotions have been consistently reported and discussed, advancing knowledge to feed theoretical and practical interests. However, as these studies are heterogeneous in the questions asked and methods used, without understanding their association, we cannot provide a clear answer to the simple question: why do people from different cultures perceive facial emotions differently? This limitation represents a bottleneck for adapting western clinical assessments cross-culturally to suit the increasing trend of globalisation in research and testing. To address this issue, we conducted a systematic review aiming to reveal the effect of culture on emotion perception from past cross-cultural studies on healthy people. We expected this review to bridge findings in basic research and clinical application.

The systematic review followed the framework outlined in Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched five databases using three groups of keywords. We included all peer-reviewed original studies that 1) conducted cross-cultural comparison in facial emotion perception with healthy adults and 2) used a design that allowed identifying specific mechanisms to explain cultural variations.

The qualitative data synthesis included three steps: 1) categorising eligible studies according to the type of cross-cultural differences they investigated, 2) summarising the findings of each cluster, and 3) summarising the mechanisms revealed by the findings.

We found the 122 eligible articles clustered into five groups that investigated 1) how race and in-group and out-group status affected facial emotion perception; 2) cultural differences in using context to identify facial expressions; 3) cultural differences in emotion conceptualisation and how they affected facial emotion perception; 4) cultural differences in interpreting facial muscle configurations; 5) how culture interacted with the inference making process.

Seven mechanisms underlying cultural variations in facial emotion perception were revealed. These are facial emotion templates, emotion conceptualisation, in/out-group differentiation, information surveying strategies, belief that expressers are independent agents, reliance on the face and other emotion expressing channels, and stereotypes. The relative importance of these factors may depend on the cultures chosen to compare and the situational settings that affect how they work together in real life.

This review, for the first time, systematically addresses the mechanisms underlying cross-cultural differences in facial emotion perception. Besides advancing knowledge about this rapidly growing area, it guides what needs to be considered when designing new tests, adapting existing tests, and assessing the risk of bias brought about by cross-cultural issues.