PARIS - Traditionally Catholic Ireland has registered almost the steepest drop worldwide in people calling themselves religious in a new survey tracking international trends in faith and atheism in recent years.

Only 47 per cent of Irish polled said they were religious people, a 22-point drop from the 69 per cent recorded in the last similar poll in 2005, according to the WIN-Gallup International network of opinion pollsters. Average religiosity in the 57 countries included in the poll was 59pc, a decline of 9 points since 2005, it said.

At the same time, the number of people declaring themselves to be convinced atheists rose from 4pc worldwide in 2005 to 7ppc this year. The biggest growth was in France.

Sinead Mooney, deputy managing director of the RED C Research company in Dublin that conducted the Irish poll, cited two factors that put Ireland just behind Vietnam as the country where religious feeling fell off most steeply.

“Obviously, there were all the scandals in the Church over that period - that was massive,” she said, referring to the repeated revelations of child sexual abuse by priests that have gravely damaged the image of Roman Catholicism there.

“Also, as countries get richer, they tend to lose some sense of religion,” she said. “We did become richer - at least at the beginning of that period.” The countries where most people self-identified as religious were Ghana (96pc), Nigeria (93pc) and Macedonia (90pc).

The most convinced atheists were found in Japan (31pc), Czech Republic (30pc) and France (29 per cent).

Identifying with a faith tradition did not always equal religiosity. Of the 51,927 people surveyed, 97 per cent of the Buddhists, 83 per cent of Protestants, 80 per cent of Hindus and 81 per cent of Catholics described themselves as religious.

The average dropped to 74 per cent among Muslims and only 38 per cent among Jews, the survey said. Africa topped the list of most devout regions of the world, with 89 per cent calling themselves religious. After that came Latin America (84 per cent), South Asia (83 per cent) and the Arab world (77 per cent).

North Asia came in the least religious at 17 per cent, followed by East Asia at 39 per cent. North America reported 57 per cent religiosity, Western Europe 51 per cent and Eastern Europe 66 per cent.

Religious attachment ran high in what the survey called global flash-points - mostly Muslim Iraq (88pc), Pakistan (84pc), Afghanistan (83 per cent) and Palestinian territories (65pc).

The survey, now being issued by the member companies in the network, offered no analysis of its results other than providing figures supporting a decades-old trend of religiosity dropping in most countries as economic development progresses.

It was not clear why Vietnam, where the communist government has allowed some religious freedom but also harassed some faith groups in recent years, led the world in the drop in religiosity.

Britain was not included in the survey because of technical problems when it was carried out from last November to January, Mooney said.