Older people are more inclined to believe in God and believe it is important to instil religion in children.
The research suggests that that population ageing can possibly slow down the transition from religious to secular values.
The study, published in the Journal for the Scientific Study of Religion, predicts that developed countries will become more religious in 20 years.
Older people (aged 50+) constitute almost one-half of the adult (aged 20+) population of developed countries, and this proportion will increase to constitute a significant majority by 2040.
"That is why, it is mainly in the developed countries that global ageing may have the most pronounced effect on slowing down the transition from religious to secular values or, possibly, even on some increase in religiosity," said one of the study authors Andrey Korotaev from the National Research University Higher School of Economics in Russia.
"For example, Japan is known to be one of the countries most affected by ageing, so probably it is not a mere coincidence that a number of important indicators reveal a slowdown of secularization trends and even a certain resurgence of religiosity in this country," Korotaev said.
It has long been observed that older people tend to be more religious than younger people.
However, it is still disputable whether this fact should be attributed to people generally becoming more religious with age per se (age effect), or to the process of secularisation, wherein earlier cohorts (to which the now older people belong) used to be more religious than those that appeared later, i.e. younger cohorts (cohort effect).
The researchers decided to analyse this issue using data from six waves of the World Values Survey in high-income countries.
A total of 16 countries were studied, including Australia, the USA, Canada, Great Britain, Israel, New Zealand, Japan, Germany, as well as other European countries.
The research showed that in high-income countries, age, rather than the cohort effect, has more impact on religiosity.
The cohort effect impacts several factors analysed by the scholars, such as church attendance and a belief in religion's importance in life, but the age effect still strongly prevails over the cohort effect.
These research results are very important for predicting the future structure of society.
( With inputs from IANS )