You’ve no doubt seen the headlines: Marriage keeps your blood pressure low. Well, at least when you’re happy in the marriage. Yet, even with that after-thought qualifier, the media got it wrong (again). Bella DePaulo took the time to actually read the original published article. Here are some of the things she found out:

• There were NO SIGNIFICANT DIFFERENCES in blood pressure [ when averaged across the 24 hours of the observational period] between the married people and the single people.
• There were NO SIGNIFICANT DIFFERENCES in blood pressure between the married people and the single people during waking hours.
• Married people look better than single people only if you compare reductions in blood pressure when the participants are unconscious [while sleeping].

I wonder what these married people dream about…

The other flaw with the media’s conclusion about this study is, as so often, their usage of a correlational study to explain causation: Even if married people had lower blood pressure than singles, that would not mean that one caused the other. As DePaulo points out, we cannot really scientifically study whether there is a causational effect because that would require an experiment with random assignment of people to the marital and single statuses, which would violate a boat-load of ethical standards. One possible way around this would be to look at longitudinal studies, which follow people for years, or even decades. No one has undertaken such a study about blood pressure yet, though the one study about marriage and happiness clearly disconfirmed the myth that married folks are happier than singles (a draft version of that study is available online).

I am also wondering what the effect of this type of media reporting has on our collective blood pressure. Like DePaulo, blatant singlism like this raises my blood pressure…