A cross-national study on religiosity and how it correlates with a variety of social problems. The result? If you want to make your country worse, give it that old time religion.
"The positive correlation between pro-theistic factors and juvenile mortality is remarkable, especially regarding absolute belief, and even prayer (Figure 4). Life spans tend to decrease as rates of religiosity rise (Figure 5), especially as a function of absolute belief. Denmark is the only exception. Unlike questionable small-scale epidemiological studies by Harris et al. and Koenig and Larson, higher rates of religious affiliation, attendance, and prayer do not result in lower juvenile-adult mortality rates on a cross-national basis.<6>"
(AR: emphasis mine)
Decrease religion, increase life-span - wow, doesn't get more combustible than that does it?
What is it about religiosity that makes lives shorter? Less respect for medical science? Faith healing?
"Although the late twentieth century STD epidemic has been curtailed in all prosperous democracies (Aral and Holmes; Panchaud et al.), rates of adolescent gonorrhea infection remain six to three hundred times higher in the U.S. than in less theistic, pro-evolution secular developed democracies"
More religion equals more likelihood of STDs. So if it burns when you pee you can say 'Thanks' to the Catholic Church that told you condoms were evil.
"Claims that secular cultures aggravate abortion rates (John Paul II) are therefore contradicted by the quantitative data. Early adolescent pregnancy and birth have dropped in the developed democracies (Abma et al.; Singh and Darroch), but rates are two to dozens of times higher in the U.S. where the decline has been more modest"
More religion leads to more abortions, and more teen pregnancies. Ignorance is bliss, indeed.
"The absence of exceptions to the negative correlation between absolute belief in a creator and acceptance of evolution, plus the lack of a significant religious revival in any developed democracy where evolution is popular, cast doubt on the thesis that societies can combine high rates of both religiosity and agreement with evolutionary science. Such an amalgamation may not be practical. By removing the need for a creator evolutionary science made belief optional. When deciding between supernatural and natural causes is a matter of opinion large numbers are likely to opt for the latter. Western nations are likely to return to the levels of popular religiosity common prior to the 1900s only in the improbable event that naturalistic evolution is scientifically overturned in favor of some form of creationist natural theology that scientifically verifies the existence of a creator. Conversely, evolution will probably not enjoy strong majority support in the U.S. until religiosity declines markedly."
(AR, emphasis mine).
In other words, the rest of the developed world has a serious advantage over the US. They are shackled by their religiosity, and giving the rest of us a huge advantage in terms of education and social policy - and until they eschew the invisible for the tangible, they will continue to hand that advantage to us.