Churches could subtly boost their income by telling people their "sins are forgiven" before passing the collection plate round, according to psychologists.
A study involving a group of devout Roman Catholics found that people who feel guilty about past misdeeds are more generous after attending confession.
The researchers from Royal Holloway in London and Oxford University observed that feeling "absolved" of sins and the feeling of "Catholic guilt" made people more inclined towards good deeds.
Previous studies have shown that strong feelings of guilt can make people do good.
That suggests that offering absolution in the confessional could be "counterproductive", the team, led by Dr Ryan McKay of Royal Holloway, said.
Writing in the journal 'Religion, Brain and Behaviour' the team asked: "If sin is a form of capital, might absolution rituals squander that capital?"
They asked a group of Catholics whether they believed in divine judgment. Each was then told to think about a sin they had committed and asked questions about how it made them feel now.
In a follow-up task they were asked how they felt when they confessed it to a priest or, if they had not, to imagine doing so.
During the process each person was given an envelope and asked to donate to the local church. Those who did so before the task involving Confession gave less money than those who did so afterwards.
"Recalling – or imagining – absolution strongly increased church donations," they concluded.
Dr McKay said: "Recent evidence has suggested that people are more likely to behave pro-socially, such as helping, sharing, donating, co-operating and volunteering, when they feel guilty.
"This raises the question of whether religious rituals of absolution, in which people are absolved of their sins and released from guilt, would actually make people less pro-social. However, the results of our study suggest the opposite – that 'releasing' people from their sin has a positive pro-social effect."
The researchers called for further research into the effects of similar confession traditions in other religions. (© Daily Telegraph, London)