People with lower IQs tend to be less happy and have poorer health in general than individuals with higher IQs, researchers from University College London reported in Psychological Medicine.As the great Linda Gottfredson has said, life is an IQ test.
The authors explained that "background happiness" and IQ (intelligent quotient) are independently associated with positive health outcomes. However, previous studies had not been consistent regarding the relationship between IQ and levels of happiness.
The same university carried out a study in 2011 which found that people with higher levels of happiness tended to have longer lifespans, regardless of their overall health status or income.
By the way, one conclusion that can be drawn from the above study is a refutation of the notion that "IQ is what IQ tests measure", and that it has no real life application. Because if that were so, we wouldn't see the robust correlation between IQ and so many other measures of life success.
Sexual liberation, the end (or non-enforcement) of victimless crime laws, and the general do-your-own-thing level to which society has descended have arguably hurt the less-intelligent peoples happiness levels. It's just so much easier to go out and do stupid, life-damaging things now, like having a baby out of wedlock (becoming a "single mother").