According to statistics by “The Annual Review of Psychology “2016 ,the number of people who have no connection to religion is sharply increasing .100 years ago the unaffiliated with religion numbered 0.2% according to Encyclopedia Britannica but today the unaffiated with religion are 16%.
1.1 Milliard people without specified religion belong to the third largest group after Christians (31.5%) and Moslems(23.2%)
then follow Hindu(15%)and others(1%)and 0.2% Judaism.
Psychology professor Ara Norenzayan from the university of British columbia researches the changes in religious belief looking at human evolution from hunters and gatherers;from small gods to one.
As communities became larger and anonymous the solution became God and fear of him.
Islam with its many strict rules have allowed punishment by god .
When living conditions are difficult there is a need for strict rules.
Police and law have replaced the need for a fear of god to control in well functioning societies.
socieites in which there is more cooperation and trust like scandinavian socieities are also the least religious.
It would be interesting to look at why those highly functioning societies contain within them foreigners born there as children of immigrants from Moslem lands who then turn against the ideal societies in which they grew up as is the case in radicalization of large numbers Moslems in Sweden and Belgium .
I have heard an Israeli rabbi explain in a discussion with a secular Israeli online that Man has been placed in the center of the universe by ancient Greek philosophy and Islam opposess this approach while Judaism sees in the center the dialogue between man and God.
Interesting ideas but i think psychology can only explain human behavior by first acknowledging the ideologies involved in various religions and political struggles with interdisciplanary information exchange. Without knowing historical processes of groups one can not claim to understand the individual motivation.
Peace,light and love