Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles.

A small number of facial expressions may be universal in that they are produced by the same basic affective states and recognized as such throughout the world. However, other aspects of emotionally expressive behavior vary widely across culture. Just why do they vary? We propose that some cultural differences in expressive behavior are determined by historical heterogeneity, or the extent to which a country's present-day population descended from migration from numerous vs. few source countries over a period of 500 y. Our reanalysis of data on cultural rules for displaying emotion from 32 countries [n = 5,340; Matsumoto D, Yoo S, Fontaine J (2008) J Cross Cult Psychol 39(1):55-74] reveals that historical heterogeneity explains substantial, unique variance in the degree to which individuals believe that emotions should be openly expressed. We also report an original study of the underlying states that people believe are signified by a smile. Cluster analysis applied to data from nine countries (n = 726), including Canada, France, Germany, India, Indonesia, Israel, Japan, New Zealand, and the United States, reveals that countries group into "cultures of smiling" determined by historical heterogeneity. Factor analysis shows that smiles sort into three social-functional subtypes: pleasure, affiliative, and dominance. The relative importance of these smile subtypes varies as a function of historical heterogeneity. These findings thus highlight the power of social-historical factors to explain cross-cultural variation in emotional expression and smile behavior.

How Universal Is a Construct of Loneliness? Measurement Invariance of the UCLA Loneliness Scale in Indonesia, Germany, and the United States.

The UCLA Loneliness Scale (ULS-20) and its short version (ULS-8) are widely used to measure loneliness. However, the question remains whether or not previous studies using the scale to measure loneliness are measuring the construct equally across countries. The present study examined the measurement invariance (MI) of both scales in Germany, Indonesia, and the United States (N = 2350). The one-, two-, and three-factor structure of the ULS-20 did not meet the model fit cut-off criteria in the total sample. The ULS-8 met the model fit cut-off criteria and has configural, but not metric invariance because two items unrelated to social isolation were not MI. The final six items (ULS-6) exclusively related to social isolation had complete MI. Participants from the United States scored highest in the ULS-6, followed by participants from Germany and then Indonesia. We conclude that the ULS-6 is an appropriate measure for cross-cultural studies on loneliness.

Is the Role of Ideologists Central in Terrorist Networks? A Social Network Analysis of Indonesian Terrorist Groups.

This study aims to describe how group leaders operate with their social ties of jihadi terrorists, using social network analysis. Data was collected through documents and interviews from terrorist detainees who were involved in jihadi terrorism activities in Indonesia. We found that relational trust with operational leaders plays an important role in terrorist social networks. More specifically, operational leaders possess a higher degree of centrality and betweenness centrality compared to ideological leaders, as operational leaders happened to possess stronger social ties (with close friends or respected authorities). Furthermore, we also found that terrorist networks in Indonesia consist of a large group of cells with low density, where members are not strongly connected to each other. The only bridges that were strong in these social networks were those involving operational leaders. This study confirmed previous studies that terrorist groups operate in a cell system, but lead to a novel finding that ideological leaders may play a limited or indirect influence in operational networks.