OPINION10 March 2015

Bias in the spotlight: system 1 and 2


In the first of a series of blogs looking at different behavioural economic biases, Crawford Hollingworth discusses the two modes of thinking: system 1 and 2.

In recent years, psychologists have proposed a theory of dual systems of the mind: System 1 and System 2. The brain is not literally divided like this, but it is a useful analogy.

  • System 1 is automatic, quick, intuitive, emotional and reactive.
  • System 2 is conscious, effortful, logical, and deliberate.

System 1 and System 2 have evolved in us for quite different reasons and therefore function very differently. To illustrate these concepts, consider the following three problems and be honest:

Problem 1: A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?

Problem 2: If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

Problem 3: In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half the lake?

(Answers at the end)

System 1 jumps up to answer these problems, but really System 2 needs to be activated to think through the right answer.

Messaging and communication is often directed toward our analytical, rational System 2, neglecting the true driver of decision-making, System 1 – which is driven by emotion and snap judgement. Most of the time, most people function using their System 1 as it requires little effort. Advertisements that generate positive feelings, such as those which feature a cute puppy or a trusted or sexy celebrity, rather than appealing to reason, play to System 1.

How can System 2 be activated?

Researchers have found that System 2, which is more reasoned and logical, can be activated in interesting ways. One experiment illustrated how students shown puzzles written in a small font in washed out grey lettering were more likely to get the puzzle right. In that example, increasing the mental effort required to read the words improved performance in solving the puzzle.

Another study found that thinking in a foreign language helped people to engage System 2. This may be because the mental effort of thinking in French or Japanese mobilised System 2. Generally speaking, making something as easy as possible is the best way to reach people – but to get deep attention some kind of challenge can create real engagement.

*Answers:5 cents,5 minutes, 47 days.

 Crawford Hollingworth is founder of The Behavioural Architects