People with low incomes are more prone to ill health due to the stress associated with their social position rather than their lack of money, according to researchers at the University of Stirling.

The researchers found that simply having low pay or low wealth wasn't enough to explain poor health; what they found to be more important was how much their income or wealth inferred about their social ranking compared with those in their neighbourhood or others like them.

The researchers were seeking to explain why the well documented link between low income and poor health occurs, even in countries like the United Kingdom where people don't have to pay for healthcare.

Lead researcher Michael Daly, from the University of Stirling's Behavioural Science Centre, said: "Our research first showed that the less people earn or own, the worse their health. This was indicated by greater reports of illness and a worse profile of common biological markers like blood pressure, cholesterol and waist circumference.

"However, all the health measures we examined were more closely related to the ranked position of the person's income or wealth compared to people of the same age, education or geographic area, rather than their income or wealth alone."

Michael Daly said: "We know from primate research that low-ranking primates can suffer chronic stress and resulting health consequences, even when food is readily available. Our study found that people who have an income that ranks lower than others tend to go on to experience poor health, while the actual amount they earn or own has no significant health effect."

The pursuit of income and wealth may only help an individual's health in so far as it also raises their social ranking. However, for every person who increases their rank another will drop a position meaning that the pursuit of income and wealth collectively is unlikely to directly improve overall health in society.

The researchers looked at data on income, wealth, and health gathered on over 40,000 adults as part of two representative longitudinal British studies, the British Household Panel Study and the English Longitudinal Study of Ageing.

The study, entitled "A Social Rank Explanation of How Money Influences Health", will be published in the Journal Health Psychology.