A Tampere University study says pessimism can significantly contribute to a person developing coronary heart disease.
The study monitored 3,000 men and women between the ages of 52 and 76 for 10 years. At the start of the study, participants were surveyed to determine how well their outlooks aligned with optimistic and pessimistic personality traits.
The study showed that pessimistic men were four times as likely to develop heart disease compared to participants deemed the least pessimistic. The most pessimistic people in the study were also more than twice as likely to die of coronary artery disease.
"It seems that pessimism alone is a risk factor for developing coronary artery disease, even when accounting for lifestyle, cholesterol and blood sugar," said Mikko Pänkäläinen, who was due to defend a dissertation on the subject at Tampere University on Friday.
Pänkäläinen said pessimists expect more bad than good things to happen. Assuming the worst in every situation also raises the body’s inflammation levels, the study found.
However being an outright optimist didn’t necessarily improve health outcomes.
"People carry both optimistic and pessimistic traits. Optimism alone wasn’t beneficial. This study found that not being too pessimistic was the main health benefit," he explained.
The study also found that pessimists have unhealthier lifestyles than people who are more positive in their outlook.
Pessimists were also less willing to improve their habits, according to Pänkäläinen.
Pessimism develops during childhood and adolescence, becoming a part of a person’s nature. The study suggests that pessimists in their 50s and 60s grew towards pessimism in their youth.
"Financial problems and difficult family circumstances experienced in childhood can cause pessimism," he said.
But won’t studies like this send those with pessimistic tendencies spiralling further down into doom and gloom?
"Pessimists can learn to think more positively, even if not changing their overall worldview," he explained.
The scientific community has previously linked depression to a greater likelihood of developing heart disease.