Groundbreaking research led by University of Limerick has revealed for the first time that the immune system directly links personality to long-term risk of death.
The study sheds new light on why people who are more conscientious tend to live longer.
Results from the new international study found that the immune system plays a previously unknown role in the link between personality traits and long-term risk of death.
Principal Investigator on the study Dr Páraic Ó Súilleabháin, from the Department of Psychology and Health Research Institute at UL, said personality was known to be associated with long-term risk of death and had been observed across numerous research studies worldwide.
“Our personality is critically important throughout our lives, from early stages in our development, to the accumulation of the impact of how we think, feel and behave across our lives, and in the years preceding our death.
“It is also becoming increasingly apparent how important personality actually is for our long-term health and resulting longevity,” Dr Ó Súilleabháin said.
It has been shown that people who have less of a tendency to be responsible, organised, and capable of self-control can be at a 40pc increased risk of future death compared with people who are more conscientious.
The UL researchers wanted to investigate if a biological pathway such as the immune system may explain why this happens.
“What is not clear is how this could happen, and importantly, what biological pathway might be responsible for this link,” added Dr Ó Súilleabháin.
The study was conducted with a team of collaborators from the Department of Psychology at UL, the Department of Psychology at West Virginia University, the Department of Psychology at Humboldt University Berlin, and the College of Medicine at Florida State University.
The study was drawing on data from the Midlife in the United States Longitudinal Study carried out on 957 adults who were examined over a 14-year period.
The researchers found that part of the reason why people who score higher on the personality trait of conscientiousness live longer is as a result of their immune system, specifically due to lower levels of a biological marker called interleukin-6.
“These findings are very important and identify for the first time that an underlying biological marker directly links personality to long-term mortality risk. With replication, these findings provide an opportunity for future interventions to increase our longevity and health across the lifespan,” Dr Ó Súilleabháin said.