One scientist writing for Science Magazine perceives the trend as follows:
"In modern nations, nonreligion and the acceptance
of evolution become popular when the
middle class majority feels sufficiently secure and safe,
thanks to low income inequality, universal health care,
job and retirement security...Religion thrives
when the majority seek the aid and protection of
supernatural powers because they are impoverished,
as in the third- and second-world countries."
Notice the following graph, where wealth is plotted against religiosity:
Interestingly, the United States is the only "First World" country that is an exception to this general trend. It has one of the highest Per Capita GDP, but it is far more religious than other "First World" countries, with around 60% of the population either 'not sure' or 'completely against' evolution.
"In the case of the United States... the majority of
Americans fear losing their middle-class status as a result
of limited government support, high levels of social pathology,
and intense economic competition and income disparity."
Particularly separating the United States from other "First World" countries is its income disparity: the wealthiest 1% of Americans own 33% of the wealth, while the wealthiest 20% of Americans own more than 80% of the wealth. According to this scientist's viewpoint, this disparity is what allows America to be wealthy and have a high religiosity at the same time. Additionally, this may not change very much, as:
"More than 60 percent of Americans whose parents scaled the top 20% of the income ladder have reached the top 20% themselves... By contrast, 65 percent of Americans with parents from the lowest fifth of earners remain stuck in the bottom two-fifths."
Given the findings, does this mean the American Dream conflicts with religious belief?
Given the US's wealth distribution, do you think the American Dream more myth or reality? Is religion merely a function of security?
*Religiosity doesn't refer to whether or not one is atheist or a believer, as one can believe in a religion but have low religiosity-- and the terms is slightly subjective. But some would calculate it by "rating prayer frequency, religious belief, importance, and church attendance," at least for Christians, according to this source.