There's one other important indicator on our Mother's Index: political status.

CNN: Why are moms in America lagging?

Although the researchers took into account a wide range of extenuating factors, including diet and exercise regimens, smoking, alcohol consumption, body mass index, and marital status, it's possible that people who drink coffee differ from the rest of the population in as-yet unidentified ways that make them less vulnerable to disease and early death.

CNN: Coffee drinking linked to longer life

When countries were classified in 1990 by their status in the United Nations Human Development Index (an index of income, literacy and health), high-development countries achieved robust and stable economic growth during 1990-98, with average growth rates of around 2.3% a year and with 35 out of 36 countries enjoying rising living standards.

ECONOMIST: By invitation