The researchers tracked 820 adults for 20 years, starting with a routine health examination in 1988. The subjects worked in various professions, from finance to manufacturing to health care. ...
The number of hours a person spent at the office didn't affect his or her longevity, nor did the niceness of the boss.
Instead, the Israeli scientists found that the factor most closely linked to health was the support of co-workers: Less-kind colleagues were associated with a higher risk of dying. While this correlation might not be surprising, the magnitude of the effect is unsettling. According to the data, middle-age workers with little or no "peer social support" in the workplace were 2.4 times more likely to die during the study.
--Jonah Lehrer, WSJ, on the importance of good colleagues. Caveat: Correlation may not be causation.