Will religion fall by the wayside as societies advance?

Comparing the degree of religious belief between countries shows some interesting results, but does it also show future trends?  One survey from a few years ago suggested a link between religion and IQ:

When he broke down the statistics, he found a strong link between intelligence and faith. Countries with a lower national IQ tended to have the most believers.

Although there were exceptions, with the most notable being the USA, perhaps due to an origin in heavily religions immigrants.  But the measurement of national IQ is at best a vague proposition.  

A more concrete metric is national development, which includes income, education levels, standard of living, etc.  This article points out a clear scale of disbelief stretching from the nearly total religious territory or sub-Saharan Africa to the secular societies of northern Europe.  Why does religious belief decline with development?  A possible factor is that people in such societies feel less fear and uncertainty about the future, and don't need whatever hope they can grasp.  Another possibility is that these people have other coping mechanisms available for life besides religion:

Even the psychological functions of religion face stiff competition today. In modern societies, when people experience psychological difficulties they turn to their doctor, psychologist, or psychiatrist. They want a scientific fix and prefer the real psychotropic medicines dished out by physicians to the metaphorical opiates offered by religion.

The upshot of the trend is that a faltering of belief is inevitable as the world advances.  That development, however, is not inevitable.  When will Sudan be like Sweden?  When will even the Appalachians be like Chicago?  But as humanists we maintain that all people have the ability to think rationally, and we present our viewpoint to all who are interested.