We're less inhibited online because we don't have to see the reaction of the person we're addressing, says Sherry Turkle, psychologist and Massachusetts Institute of Technology professor of the social studies of science and technology.

WSJ: Why We Are So Rude on Facebook and Other Social Media

The Elsa research team, which comprises researchers from UCL, NatCen Social Research, the University of Manchester, and the Institute for Fiscal Studies, found the wealthier over-50s were half as likely to become socially isolated than the least wealthy.

BBC: Enjoyment of life 'key to living longer'

"Chinese Strategic, Economic and Social View of Vietnam", edited by Gu Xiaosong and Sheng Lijun, Institute for South-East Asian Studies, Singapore, 2005.

ECONOMIST: Sources and acknowledgments

Alma Sultangalieva, the director of the Kazakhstan Institute for Strategic Studies, views the development of Islamic dissent in the industrialised parts of the Fergana Valley more as a social issue triggered by high unemployment.

ECONOMIST: Central Asia