This article from reason explains that hope — although it does not explain it in terms of hope — is the (?) basis for satisfaction:
Stavrova and company concluded that the “correlation between a belief in scientific–technological progress and life satisfaction was positive and significant in 69 of the 72 countries.” On the other hand, the relationship between religiosity and life satisfaction was positive in only 28 countries and actually negative in 5 countries. Similarly, belief in sci-tech progress correlated with a sense of personal control in 67 countries, whereas religiosity was positively associated with personal control in only 23 countries—and was negative in 10 countries.
Stavrova and her colleagues speculate that this negative association between a belief in God and a sense of personal control might arise from dispositional differences. Primary control strategies aim to change the external world so that it fits with one’s personal needs and desires; secondary control strategies seek to change personal needs and desires so that they fit with the external world. Earlier research has found that religious believers tend to score higher on secondary than primary control strategies. Stavrova and her fellow researchers suggest that future studies might “examine whether a belief in scientific–technological progress, in contrast to a religious belief, entails individuals to rely more on primary rather than secondary control strategies.”
So why do people who believe in sci-tech progress tend to be happier than the religious faithful? Stavrova and her colleagues propose that “achieving control over the world and mastering the environment has always been one of the major goals of science. Believing that science is or will prospectively grant such mastery of nature imbues individuals with the belief that they are in control of their lives.” This sense of personal control in turn contributes to a higher life satisfaction.
It turns out that people who rely upon the efficacy of the human intellect to solve problems have a greater chance of living satisfying lives than those who cling to the supernatural hope that an unseen sky-God will somehow save them from their troubles.
A few things here: I certainly don’t believe bare “religious belief” matters much at all. In fact, I would hold that his belief in “science” is a “religious belief”. Belief can never be better than its object: the study merely looks at “religious belief” as if all religious belief were interchangeable. It does not consider the certainty of that belief.
It is the Scriptural position that most “religious belief” is false and rebellious.
Second, there is no apparent control for circumstances. I suspect that most of the people who hold to the “sci-tech progress” and well-educated, relatively prosperous and younger. In such a circumstance “sci-tech” has relatively little work to do. A comfortable, sociable, reasonably attractive 30 year old is probably happier than other people: but such happiness hinges upon circumstance.
I would be curious of the satisfaction of a “sic-tech progress” believer on the day they learn their child has cancer.
As a Christian (and often a poor specimen), I know that there is no promise of endless happiness now. In fact, the promise is precisely the opposite. I am hopeful; but I also know the realism that this world as a painful one. I know that making a better device will not alter the human heart. I know that no amount of medical technology (for which I am very grateful) will ever ultimately put off death.
I know that cultist and idolators often begin joyful.
Another aspect: personal control. Any belief in “personal control” is on its face irrational — although the desire for personal utter autonomy has been a human goal since the Garden.