Impatient people may be more likely to have shorter telomeres, parts of human chromosomes that that tend to get shorter as people age, according to a new study.
Previous research has shown that people with shorter telomeres may be more likely to develop common diseases associated with aging — such as cancers, diabetes and cardiovascular diseases — compared with people who have longer telomeres, the researchers said.
The new study shows for the first time that impatience is linked to people's telomere length, said study co-author Soo Hong Chew, a professor of economics at the National University of Singapore.
In the study, researchers looked at the relationship between impatience and telomere length among 1,158 undergraduate students in Singapore. The researchers measured the participants' levels of impatience by asking them to choose between receiving a smaller amount of money in a day or more money later. [7 Thoughts That Are Bad for You]
The participants also underwent a blood test, so the researchers could assess the length of the individuals' telomeres, the protective "caps" at the ends of chromosomes. These structures defend the rest of the chromosome from the erosion, or shortening, that happens each time a cell divides.
In the first task in the study, the researchers asked the people to choose between receiving $100 the next day and receiving $101 in about a month.
In the second task, the participants had to chose between receiving $100 the next day and receiving $104 about a month later. Over a series of eight more tasks, the researchers gradually increased the amount in the second option, so that, by the last task, it involved receiving $128 in about a month's time. Meanwhile, the first option remained unchanged, at $100 the following day.
The higher the amount of money it took to convince a person to delay receiving the financial reward by a month, the higher was that person's level of impatience, the investigators said.
Results showed that the people who had higher levels of impatience tended to have shorter telomeres than the individuals who had lower levels of impatience.
The researchers did not examine whether the shorter telomeres in the more impatient people in the study translated into actual effects on their health. However, previous research has shown "that telomere length serves as an early predictor of onset of diseases and earlier mortality," Chew told Live Science.
The new study found an association, but not a cause-and-effect relationship, between impatience and shorter telomeres. It is unclear if having shorter telomeres may lead to higher levels of impatience, or if being more impatient may lead to having shorter telomeres — or if some other factor underlies both, the researchers said.
However, previous research has linked impatience to an overall inability to deal with life's frustrations, and an increased risk of mental disorders, Chew said. This makes the researchers think that impatience may actually lead to having shorter telomeres, he said.
The researchers also found that the link between shorter telomeres and impatience was more pronounced in women than in men, which suggests that women's telomeres might be more sensitive to the effects of impatience, compared with men's telomeres. This finding is in line with previous research showing that other psychological factors, such as stress, are linked to the DNA damage involved in telomere shortening, in women but not in men.
The researchers are now planning to conduct a follow-up study that may better characterize the relationship between telomere length and impatience, they said. In that study, they intend to see if trying to enhance people's patience through a mindfulness-based training might help preserve the individuals' telomere length, the researchers said.
The new study was published today (Feb. 22) in the journal PNAS.