Gap year volunteers are in danger of becoming the new colonialists, indulging in a type of “charity tourism” that can do more harm than good, according to a leading charity.

The gap year has become a rite of passage between school and university as students cast off their daily lives and head for developing nations in Africa, Asia or South America.

It is seen as a chance to broaden horizons, learn about other cultures and make a positive contribution to the world.

Organising volunteering programmes is now big business. Too often, however, the schemes are designed with the enjoyment of the volunteers in mind. Too little concern is shown for the communities they are supposed to be helping, according to Judith Brodie, a director of Voluntary Service Overseas (VSO).

“Some gap year providers seem to pay little attention to whether young people are actually making any long-term difference to the communities they are working in,” she said.

“It’s an ‘all about us’ attitude. There seems to be a colonial attitude, whereby it is assumed that just because a young person is from the UK, they will be of benefit to their host community.”

VSO cites the case of a gap year student who was asked to survey an endangered coral reef in Madagascar only to find that the work was pointless because the reef had been surveyed countless times by previous volunteers.

In the worst instances, unskilled 18-year-old volunteers from Britain could do more harm than good, Ms Brodie added. “They could be a drain on resources of their host communities if they need training and support all the time.”

Ms Brodie stressed that young volunteers should not expect to “have a great time at the expense of others”.

VSO avoided this, she said, by ensuring that its volunteers worked in a mutually co-operative way with communities. It also arranged for students from developing nations to volunteer in Britain.

Kate Simpson, a visiting fellow at the University of Newcastle upon Tyne and the founder of ethicalvolunteering.org, which gives advice to those volunteering overseas, agreed that some schemes could seem colonial.

“It’s particularly problematic when volunteers are engaged to do the kind of work they would not be allowed to do in the UK,” she said. “We wouldn’t dream of having unskilled teenagers working in a hospital or teaching a class in the UK.”

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