Men who are socially awkward and shun contact with people are more likely to die of heart disease than their more gregarious peers, according to research that sheds light on how personality can influence health.

A 30-year study of 2,100 men has revealed that withdrawn introverts who engage in “social avoidance” have a higher risk of death from heart attacks, strokes and other forms of cardiovascular disease, when compared with other men of similar age and social class.

The findings are the latest to show that particular character traits can have a profound effect on men’s health, probably as a result of stress.

Heart attacks are already known to be more common among men with “type A” personalities, who tend to be aggressive, bossy, short-tempered and in a hurry to get things done.

The research indicates that the same is also true of a very different class of men, those with “type D” personalities, who find it difficult to mix with other people and who tend to avoid having contact with others when they can help it.

In the study, which is published in the journal Annals of Epidemiology, a team from Northwestern University in Chicago led by Jarett Berry and Philip Greenland looked at data from a cohort of men recruited in 1957.

All had been working for the Western Electric Company’s Hawthorne Works in Chicago, and were aged between 40 and 55 when they began being monitored. Of the 2,080 men who participated, 404 had died of coronary heart disease 30 years after the start of the study, and 541 had died of other kinds of cardiovascular disease. A further 412 had died of other causes.

The Northwestern team’s analysis found that men who scored highly for social avoidance were about 40 per cent more likely to die of a cardiovascular cause than those who were found to be most outgoing. No effect was found for other causes of death.

“These findings suggest the possibility that social avoidance might increase the risk for cardiovascular disease death specifically, but not for other common causes of death,” the scientists said.

Though the study did not investigate why the most withdrawn men were at greater risk of heart disease and other cardiovascular problems, the effect is thought likely to be linked to higher levels of stress.

Previous research has shown that children and adults who are shy and inhibited have heightened physiological responses to unfamiliar situations, with higher heart rates, blood pressure and levels of stress-related hormones.

It is also known that certain kinds of social contact, such as having a large group of friends and marrying, can have a protective effect against many health problems.

It is possible that personality traits also affect health by changing lifestyle and behaviour, for example by influencing diet or exercise. The Northwestern study, however, found no link between social avoidance and factors such as smoking or alcohol consumption that might explain the men’s higher risk of heart disease.

Social avoidance is a trait that usually emerges during childhood. “The tendency to avoid social contact reflects a broader temperament pattern characterised by a generalised fear of unfamiliarity, that can be observed consistently throughout childhood and into adulthood,” the scientists said.

Which one are you?

— Type A

Impatient, competitive, overachieving workaholics. Can be aggressive and prone to perfectionism. They live by timetables and cannot relax and are insecure. They are at higher risk of heart disease

Example: Edmund Blackadder

— Type B

Patient, easygoing, relaxed and content with their lot. Calm and rational, Type Bs have the best long-term health outlook

Example: Homer Simpson

— Type C

Have difficulty expressing emotion. Eager to please, conforming and introverted. Self-controlled and prone to severe stress as a result. This personality type was first identified among cancer patients

Example: Charles (Hugh Grant) from Four Weddings and a Funeral

— Type D

Consciously suppress their feelings. They tend to be worried, gloomy and anxious, shy and insecure, lacking assertiveness and self-confidence. Type D people are at higher risk of recurrent heart attack

Example: Eeyore

Sources: National Council of Psychotherapists, Times database

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