Research has shown, for the first time that the comparatively longer lifespan of intelligent people are associated with their genes. Published in the International Journal of epidemiology, the study is the first to evaluate a possible link between genetics, intelligence and lifespan.
Conducting the Study With Twins
Rosalind Arden, a Research Associate at London School of Economics and Political Science (LSE) explained that according to previous studies, children with a higher IQ were prone to having longer lifespans. Moreover, people with better employments, such as senior civil servants, live longer as well. However, the exact reason behind this phenomenon was not clearly understood.
Forming comparisons between genetically identical and fraternal twins (share half of the DNA of their twin) helps scientists study the influence of genes effectively. It also helps in distinguishing the later from environmental factors, such as nutrition, schooling and housing.
For the purpose of this study, the researchers examined three different twin studies from US, Denmark and Sweden. In all three studies, records of intelligence were maintained, and at least one twin had died, and the age of death was also recorded. Moreover, only same-sex twins were included in all studies.
Analysis revealed that 95 percent of the association between intelligence and a longer lifespan was due to genetics. Researchers found that, within twin pairs, the more intelligent twin generally outlived the less intelligent one, and this trend was much more evident in fraternal (non-identical) twins.
This shows that the link between top jobs and a longer lifespan has more to do with genes than simply having a bigger desk.
Explaining The Results: Why Intelligent People Live Longer
“It could be possible that people who have genes that make them brighter also have genes for a healthier body”, elaborated Arden. “Or that intelligence and lifespan are both sensitive to overall mutations – people with fewer genetic mutations tend to be more intelligent and thus live longer”.
Whatever the explanation, it must be noted that the link between intelligence and lifespan is small. Thus, it’s not appropriate to determine how long a person would live by simply looking at his or her exam results. Continued testing and research into these aspects will lead to a full understanding of the underlying mechanisms.