The reason climate change has become such a divisive issue could be down to what behavioural scientist Nick Chater calls ‘attribute substitution’.

Climate change has provoked much debate, with some arguing that humanity’s production of greenhouse gases is heating up the Earth, while sceptics dismiss the notion.

Professor Chater revealed in the first episode of the second series of BBC Radio 4’s The Human Zoo how people look to find simple short-cuts to a very complex issue such as the debate around climate change. Attribute substitution – where a person replaces a complicated question that needs a judgement with a more easily calculated attribute – underlies these short-cuts.

“When you look at the climate change argument you can see this at play,” said Professor Chater, of Warwick Business School. “A recent large scale web survey on a single day across the world asked the question ‘just how much do you believe that climate change is real?’

“It wanted to see how much that judgment was affected by whether the temperature of the particular location was hotter or colder than average for that time of the year. It found that if it is hotter than average on that day, then people tend to think there is something in climate change, but if it is a colder than average day they tend to be more sceptical.

“It indicates we are being pushed around by very immediate things, like what we see when we look out the window. That really does affect our overall views of how the world works on an almost moment by moment basis.”

A separate experiment on students at Warwick Business School showed how the same data could be interpreted differently by those who believe in climate change and those that don’t.

“We gave them a graph with a wiggly line on it and asked the students to continue it in the way that seemed most natural,” said Professor Chater. “We then gave them another wiggly line, but this time it was real data plotting the average global temperature from 1880 to 2010, and told them it was a climate change prediction task and to guess how that graph would continue. Then on a scale of one to seven we asked them how worried they were by climate change.

“We found that if somebody thinks climate change is real, they tend to extrapolate upwards in temperature more than people who have the opposite view. That is true when they think the data is about climate change but not true when they see the wiggly pattern has no particular meaning. And when people are more sceptical they tend to keep the line flatter.

“It shows it is very hard for us to look at data in a dispassionate way. When we consider how data is going to continue we think both about what it shows so far but also what our general knowledge or beliefs tell us.

“There is a danger it can mean the data can look different depending on your perspective. If I am a climate change sceptic I might look at the same data and think that doesn’t show much of a trend upwards, but somebody who strongly believes in climate change might look at the same data and see a much more alarming trend.”

When faced with complex issues, finding short-cuts like attribute substitutions is, Professor Chater says, a perfectly rational thing to do.

“Attribute substitution is part of a more general tendency to find short-cuts to difficult problems and that gets you quite a long way,” said the Professor of Behavioural Science. “If you are wondering how large a city is you might think it is famous, it has an enormous river flowing through it, a well-known football team and so think it is a large city. It is using available simple information to solve a difficult problem and on the whole that works pretty well.

“We live in an enormously complex world so these simplifications and short-cuts are essential, even though they produce biases, they allow us to work and behave.”

To listen to The Human Zoo click here and to take part in the programme’s online lab experiments click here.

Behavioural science is at the core of the Warwick MBA by full-time study. Professor Nick Chater also teaches Behavioural Sciences for the Manager on the Warwick Executive MBA and Principles of Cognition on MSc Business (Behavioural Science).

Find out more about Behavioural Science by watching our film here.