Public Release:  Herd mentality: Are we programmed to make bad decisions?

University of Exeter

A natural desire to be part of the 'in crowd' could damage our ability to make the right decisions, a new study has shown.

Research led by the University of Exeter has shown that individuals have evolved to be overly influenced by their neighbours, rather than rely on their own instinct. As a result, groups become less responsive to changes in their natural environment.

The collaborative international study, which includes academics from Princeton University and both the Sorbonne Universites and Institute for Research in Computer Science and Automation (INRIA) in France, is published in the Royal Society journal Interface.

Lead author of the report, Dr Colin Torney, from the University of Exeter's Mathematics department explained: "Social influence is a powerful force in nature and society.

"Copying what other individuals do can be useful in many situations, such as what kind of phone to buy, or for animals, which way to move or whether a situation is dangerous.

"However, the challenge is in evaluating personal beliefs when they contradict what others are doing. We showed that evolution will lead individuals to over use social information, and copy others too much than they should.

"The result is that groups evolve to be unresponsive to changes in their environment and spend too much time copying one another, and not making their own decisions. "

The team used mathematical models to look at how the use of social information has evolved within animal groups.

By using a simple model of decision-making in a dynamic environment, the team were able to show that individuals overly rely on social information and evolve to be too readily influenced by their neighbours. The team suggest this is due to a "classic evolutionary conflict between individual and collective interest".

Dr Torney said: "Our results suggest we shouldn't expect social groups in nature to respond effectively to changing environments. Individuals that spend too much time copying their neighbours is likely to be the norm."

The study, Social information use and the evolution of unresponsiveness in collective systems, is published in the journal Interface on December 17 2014.

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About the University of Exeter

The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 19,000 students and is ranked 7th in The Times and The Sunday Times Good University Guide league table, 10th in The Complete University Guide and 12th in the Guardian University Guide 2014. In the 2008 Research Assessment Exercise (RAE) 90% of the University's research was rated as being at internationally recognised levels and 16 of its 31 subjects are ranked in the top 10, with 27 subjects ranked in the top 20. Exeter was The Sunday Times University of the Year 2012-13.

The University has four campuses. The Streatham and St Luke's campuses are in Exeter and there are two campuses in Cornwall, Penryn and Truro. The 2014-2015 academic year marks the 10-year anniversary of the two Cornwall campuses. In a pioneering arrangement in the UK, the Penryn Campus is owned and jointly managed with Falmouth University. At the campus, University of Exeter students can study programmes in the following areas: Animal Behaviour, Conservation Biology and Ecology, English, Environmental Science, Evolutionary Biology, Geography, Geology, History, Human Sciences, Mining and Minerals Engineering, Politics and International Relations, Renewable Energy and Zoology.

The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the past few years; including landmark new student services centres - the Forum in Exeter and The Exchange at Penryn - together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.

http://www.exeter.ac.uk/cornwall

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