People who earn low scores on intelligence tests in their early life run a higher risk of suicide and suicide attempt later in life, a study from Karolinska Institutet in Sweden claims.
The researchers followed almost 50,000 Swedish men from the 1970s until recently, to reach their findings.
Intelligence and emotional control
Previous studies have linked low intelligence and low emotional control to an increased risk of suicide. This study adds to a growing literature by showing how this tendency develops over time.
By looking at individuals over the course of 40 years, the new study showed that the risk of suicide later in life stayed high in people who showed low intelligence in their younger years. Those with low emotional control, however, were shown to be more likely to improve over time.
"The most interesting aspect of this study is that the negative effect of low emotional stability is strongest in adolescence," Alma Sörberg Wallin, a psychologist at the Department of Public Health Sciences at Karolinska Institutet and one of the study's authors, said in a press release.
"Among people in their 50s, the association between low emotional stability and suicide is much weaker. That adds a certain level of hope and supports the description of suicide as a permanent solution to a temporary problem."
In order to compare intelligence and emotional control with suicidal behavior, the scientists divided the men into a scale of five levels.
Each scale corresponded to IQ bands that ranged from less than 82 to more than 126, as well as emotional control measurements ranging from one (very low) to five (very high).
Death and hospital discharge registers were then used to identify attempted suicides and suicides that had occured between 1973-2008.
The study shows that individuals with the lowest scale of intelligence were approximately six times more likely to attempt suicide compared with people on the highest intelligence scale.
A similar trend was shown on emotional control. Men with the least emotional control were almost seven times more likely to show suicidal behavior than men in the highest category. Those with emotional control problems were more likely to improve over time.
Preventative care and support
"Intelligence is strongly linked to educational success, and without a high educational degree you are more likely to end up in a low socioeconomic position or become unemployed," Nora Hansson Bittár, psychology student and the study's main author, said in the press release.
"This highlights the need for support and preventive measures. No one should end up in such a vulnerable situation that suicide appears to be the only way out."
The study is published in the journal Psychological Medicine.