On wealth and the diversity of friendships: high social class people around the world have fewer international friends

Having international social ties carries many potential advantages, including access to novel ideas and greater commercial opportunities. Yet little is known about who forms more international friendships. Here, we propose social class plays a key role in determining people's internationalism. We conducted two studies to test whether social class is related positively to internationalism (the building social class hypothesis) or negatively to internationalism (the restricting social class hypothesis). In Study 1, we found that among individuals in the United States, social class was negatively related to percentage of friends on Facebook that are outside the United States. In Study 2, we extended these findings to the global level by analyzing country-level data on Facebook friends formed in 2011 (nearly 50 billion friendships) across 187 countries. We found that people from higher social class countries (as indexed by GDP per capita) had lower levels of internationalism—that is, they made more friendships domestically than abroad

Laughter conveys status

We propose that status influences individuals' use of dominant versus submissive laughter, and that individuals are conferred status based on the way they laugh. In Study 1, naturally occurring laughter was observed while low- and high-status individuals teased one another. The use of dominant and submissive laughter corresponded to hierarchical variables: High-status individuals and teasers displayed more dominant, disinhibited laughs, whereas low-status individuals and targets of teases displayed more submissive, inhibited laughs. Further, low-status individuals were more likely to vary the form of their laughter between contexts than high-status individuals. Study 2 demonstrated that laughter influences perceptions of status by naïve observers. Individuals who laughed dominantly were afforded higher status than individuals who laughed submissively, regardless of their actual status. Moreover, low-status laughers were perceived to be significantly higher in status, and to have as much status as high-status laughers, when laughing dominantly versus submissively. Finally, exploratory analyses suggest that the positive emotional reactions of observers of laughter can help explain the link between laugh type and status perceptions

Anticoagulation in patients with atrial fibrillation, thrombocytopenia and hematological malignancy

Managing anticoagulation in hematological malignancy patients with atrial fibrillation and thrombocytopenia is a clinical challenge with limited data. We aimed to identify anticoagulation management strategies and evaluate bleeding and thrombosis rates associated with each approach. A retrospective cohort study in Israel and the Netherlands was conducted. Patients with hematological malignancy and atrial fibrillation were indexed when platelets were < 50 x 10(9)/L and followed for 30 days. The cohort included 61 patients of whom 42 (69%) had anticoagulation held at index. On multivariate analysis, holding anticoagulation was associated with age < 65 years and atrial fibrillation diagnosed within 30 days prior index. Clinically relevant bleeding was diagnosed in 7 (16.7%) and 1 (5.3%) of patients who had anticoagulation held and continued respectively, while arterial thromboembolism occurred in 1 patient in each group (2.4% and 5.3%, respectively). All-cause mortality rate was high at 45%. Accordingly, the 30-day bleeding risk may outweigh the risk of arterial thromboembolism in hematological malignancy, platelets < 50 x 10(9)/L and atrial fibrillation