Rational Thinking & Intuitive Thinking: The Dual Process Model (SL IB Psychology)

What is the Dual Process Model?

• The Dual Process Model (DPM) is a conceptual framework in which the process of thinking and decision-making is presented
• Decision-making cannot be reached without someone first having thought through the relative options available hence the two are inextricably linked
• Wason & Evans first proposed the DPM in 1975 as a way of highlighting the idea that human beings utilise two different systems of thinking: one is ‘fast’ - intuitive thinking known as System 1 (S1) and the other is ‘slow’ - rational thinking known as System 2 (S2)

S1 - System 1

• S1 thinking happens on an automatic level, requiring little effort or time; it is prone to bias and heuristics which can result in mistakes, errors and inaccuracies
• S1 is not a ‘bad’ way of thinking as it saves time and energy, is based to a large part on instinctive responses which may be crucial in situations where split-second responses are required, and is holistic i.e. it uses past experiences and learning to enable the decision to be made
• S1 is best used for decisions such as choosing which pizza topping to have, crossing a road quickly to avoid oncoming traffic and it can be seen in the behaviour of an experienced driver who goes into ‘automatic mode’ when driving i.e. they don’t have to focus on the actual process of driving

S2 - System 2

• S2 is slower, effortful and analytical, is only used by humans as it involves higher-order information processing and is more likely to mean that decisions reached and problems solved are accurate and reliable
• S2 is not the ‘best’ way of thinking as it uses a lot of cognitive energy (which human beings do not enjoy as we are cognitive misers) and for the majority of day-to-day decisions it is unnecessary
• S2 is best used for decisions such as buying a house, preparing for a job interview and it can be seen in the behaviour of a learner driver who needs to concentrate on the actual process of driving as it has not become automatic for them yet

Both systems interact and work together: at times S2 may override S1 if circumstances dictate that this is the best course of action (though this is not true for all people and all situations, it will largely depend on the variables at play in each situation)

For some people choosing a pizza topping may require S2 thinking…

Which research studies investigate the DPM?

• Alter et al. (2007) – the use of disfluent font linked to S2 thinking in participants
• Lerner & Ma-Kellams (2016) – empathy linked to S2 thinking

Alter et al. (2007) and Lerner & Mal-Kellams (2016) are available as separate Key Studies – just navigate the Cognitive Processing section of this topic to find it (Two Key Studies of Thinking & Decision-Making)

Evaluation of the Dual Process Model

Strengths

• The model provides a compelling explanation of ‘thinking fast and slow’ which is easily applicable to a range of situations i.e it has good validity
• The model could be used to improve decision making in key environments such as business, education, policy-making etc.

Weaknesses

• The model is good at explaining what may be at the root of thinking and decision-making but it is not so good at explaining how S1 and S2 work
• Trying to operationalise both S1 and S2 thinking is difficult which means that research in this field is not entirely conclusive as to which system is being used during the set tasks