Intelligence predicts health and longevity

Large epidemiological studies of almost an entire population in Scotland have found that intelligence (as measured by an IQ-type test) in childhood predicts substantial differences in adult morbidity and mortality, including deaths from cancers and cardiovascular diseases.  These differences remain significant after controlling for socioeconomic variables.

Here is the full article, courtesy of Randall Parker.  It suggests another perspective on why health care appears not to contribute to health.  Gross health care expenditures — an input — are not always the best way to measure real health care outputs.  (Similarly, gross educational expenditures do not much predict learning, once we adjust for other factors.)  High IQ is correlated with compliance with doctors’ instructions, good choice of doctor, adequate medical attention, and so on.  High IQ thus appears to be doing some of the work that should be credited to health care, as properly defined and measured.

Policy implications: Targeting gross expenditures on health is not the best approach to making people healthy.  But this does not mean that health is neutral with respect to health care policies.  A smart policy can make people much better off, just as smart patients live longer.

My next question: Do veterinarians extend the lives of the animals they care for?