A study of more than 300,000 donations has confirmed the fundraising axiom that donors are heavily influenced by what other people give.

The extent to which they are influenced, however, may be more of a surprise. A University of Bristol study, which monitored 300,000 donations made on 10,000 different Virgin Money Giving and JustGiving pages over the 2010 London Marathon, found large donations could boost further donation averages by an additional 50 per cent.

A single donation of £100 on such pages boosts the average donation amount of up to the next 20 donations from around £20 to £30.

Small donations have a similarly strong, but negative, effect. A low donation will inspire other donors to drop their average gift by around £5.

Professor Sarah Smith, from the university’s Centre for Market and Public Organisation, said: “What is interesting is the sheer scale of the effect.

“It isn’t as simple as donors competing to be the most generous – or avoiding being the meanest. Instead, it looks like they are trying to find what they think is the right level for them personally, compared to their peers.”