Got a handle on your supermarket spending? A new trolley design could loosen your grip

It is usually treats and offers surrounding supermarket checkouts that end up burning holes in our pockets – but now it has been revealed that shopping trolleys themselves could lead to us spending more.

A study has found that removing the horizontal grip bar on trolleys and replacing it with handles like those on a wheelbarrow could lead to shoppers spending 25 per cent more.

Researchers from City University of London's Bayes Business School and the University of Innsbruck, in Austria, tested a new trolley design based on psychological research.

The research "has proven that triceps activation is associated with rejecting things we don't like – for example when we push or hold something away from us – while biceps activation is associated with things we do like, for example when we pull or hold something close to our body".

Prof Zachary Estes and Prof Mathias Streicher used the changed trolley design to survey 2,359 shoppers over three days. They discovered that people using it bought more products and spent 25 per cent more than those using standard trolleys.

The findings indicate that retailers are likely to chalk up greater profits by providing customers with trolleys with parallel handles, while people are likely to exercise more control over their spending if they are using a standard trolley.

The researchers have held talks about the findings with leading supermarket chains in Austria and the US.

Prof Estes, a professor in marketing at Bayes Business School, said most shoppers had indicated that they preferred the standard trolley design but added: "We don't know if that's just because they’re used to them.

"We think it's just a matter of being used to something and then, after one or two trips to the supermarkets with the new trolleys, people will just become accustomed to them and think they're normal and they won't be uncomfortable any more."

The study is published in the Journal of Marketing.

Prof Estes said: "It is shocking to find that making a small change to the position of handles can have such a large impact on shoppers' spending. Indeed, the handles literally cause us to flex our shopping muscles."