In 2001, L. Whalley of the University of Northern Iowa and I.J. Deary of the University of Edinburgh published a paper on the relationship between intelligence and longevity. In 1932, 2,792 11-year-old Scottish children were assessed for intelligence. Decades later, in 1997, scientists analyzed this data when nearly 80% of respondents had already died. IQ levels were found to be correlated with how many years each of these children would live out in adulthood. For example, a low IQ of 30 as a child almost halved the individual’s odds of reaching the age of 76.
J.L. Zagorsky of Boston University published a paper in 2007 comparing people’s IQs with their incomes. A total of 7,500 questionnaires, filled out by people aged 33 to 41, were analyzed as part of the study. It was possible to calculate that each IQ point on average increased one’s annual income by $616 (higher now, due to inflation). That is, a difference of tens of IQ points could mean a dramatic increase in income. However, in parallel with the positive implications, the researchers drew attention to the fact that people with higher intelligence also had a higher likelihood of declaring bankruptcy.
In 2012, A. Rosenblad et al. from Stockholm University published a paper in which they demonstrated the influence of intelligence on the amount of weight gained in the future. The observation of 5,286 Swedish men began when they were 18 years old and ended when they reached the age of 40. There was a clear correlation between IQ scores and the study participants’ weight. Men with a low level of intelligence gained approximately 40% more excess weight over the 22 years than their more intellectually capable counterparts.
C.R. Gale et al. of the University of Edinburgh published a paper in 2009 on the relationship between intelligence and psychological distress. For these purposes, general cognitive skills were measured in two groups of people at the age of 10 and 11. The same participants were later tested for levels of severe distress at the ages of 30 and 33 years. Based on the data collected from the nearly 12,000 people in the sample, the scientists saw that high intelligence reduced distress in adulthood by 23% or even 39% (depending on the group).