This gets my vote for most important research finding of the year (my emphasis):

“How tall your parents are compared to the average height explains 80 to 90 percent of how tall you are compared to the average person,” Dr. Vaupel said. But “only 3 percent of how long you live compared to the average person can be explained by how long your parents lived.

…Matt McGue, a psychology professor at the University of Minnesota who studies twins, contrasts life spans with personality, which, he says, is about 50 percent heritable, or attention-deficit hyperactivity disorder, which is 70 to 80 percent heritable, or body weight, which is 70 percent heritable.

“I’ve been in this business for a long while, and life span is probably one of the most weakly heritable traits I’ve ever studied,” Dr. McGue said.

I challenge somebody to explain this finding.

I am in shock, because I have always read that characteristics that we know are associated with longevity, including race, IQ, and weight, are highly heritable. In fact, if weight is 70 percent heritable and longevity is only 3 percent heritable, how can anybody find a connection between weight and longevity? Is the connection statistically significant, but so small that it is swamped by random variation in longevity?

If I were allocating money for medical research, I’d throw a bit more at the oddballs who are studying bacteria in the gut as a source of disease and a bit less at the folks massaging the genome.