The study, published in the journal Psychological Medicine, is the first to demonstrate the role of socio-economic and clinical factors, providing new insight into the relationship between IQ and happiness.
Researchers from UCL analysed data from the 2007 Adult Psychiatric Morbidity Survey in England, which was designed to be representative of people living in private households. Aged 16 or over, the 6,870 participants were interviewed about their education, health, income, and social life; happiness was measured on a three point scale and verbal IQ estimated using the National Adult Reading Test (NART).
In particular, people in the lower IQ range (70-89) – who comprise around 15% of the UK population – are more likely to be socially disadvantaged and less happy compared to people with higher IQ, and have a higher prevalence of common mental disorders and suicidal behaviour.
“We found that IQ is associated with self-reported happiness, as levels of happiness were lowest in the lower IQ groups and highest in the higher IQ groups,” said lead author Dr Angela Hassiotis (UCL Mental Health Sciences Unit). “This is particularly relevant when considering the current political debates on happiness.”
When looking at the data we saw that people with a lower IQ were less likely to be happier because of higher levels of socio-economic disadvantage such as lower income
Dr Angela Hassiotis
“When looking at the data we saw that people with a lower IQ were less likely to be happier because of higher levels of socio-economic disadvantage such as lower income,” added Dr Hassiotis. “They are also less likely to be happy because they need more help with skills of daily living, have poorer health and report more symptoms of psychological distress.”
“Our findings provide evidence for the need to better support people in this group,” said Dr Afia Ali (UCL Mental Health Sciences Unit), co-author of the study. “Interventions that reduce these social inequalities could improve levels of happiness in people with lower IQ.”
Approaches may include the promotion of programmes that tackle education and long term unemployment; improving physical health through targeted health promotion in primary care; and managing mental ill health through pro-active detection and treatment with a focus on those with milder forms of cognitive and social impairments.
“There is also some evidence that long term intensive strategies directed at young children from socially deprived backgrounds can have a positive impact not only on IQ but also on wellbeing and life opportunities,” said Dr Hassiotis. ”Such interventions are likely to be costly but the initial costs may be offset by future benefits such as a reduced reliance on state benefits and better mental and physical health.”