And control seems to have been one factor at work in the Whitehall study.

The first of the Whitehall studies, or Whitehall I, found higher mortality rates due to all causes for men of lower employment grade.

The initial Whitehall study found lower grades, and thus status, were clearly associated with higher prevalence of significant risk factors.

The name Whitehall II was derived from the previous Whitehall study.

The primary health risks under investigation in the Whitehall studies include cardiovascular function, smoking, car ownership, angina, leisure and hobbies, ECG measurements, and diabetes.

Summing up the moral of the Whitehall studies, the researchers concluded that "more attention should be paid to the social environments, job design, and the consequences of income inequality."

Currently there is no universally-accepted cause for the phenomenon brought to light by the Whitehall studies.

In the so-called Whitehall studies of British civil servants, for example, researchers have found that an individual's occupational grade was strongly correlated to longevity: the higher the grade, the longer the life.

Successful collaboration during the first Whitehall study made it easier to agree on potentially difficult issues such as obtaining sickness absence records from the pay centres.

Most famous for linking social status with health are the Whitehall studies - a series of studies conducted on civil servants in London.