Abstract
Dual Process Theory argues there are two systems people use to make decisions, System 1 and System 2. System 1 is fast, automatic, and intuitive while System 2 is slow, deliberate, and analytical. System 2 is often portrayed as the recommended process, due to evidence that System 1 results in biases in judgment which can lead to irrational choices. However, much of this evidence comes from laboratory experiments with normative right and wrong answers, often determined using maths or statistics. Decision contexts in the real world do not conform to normative models, therefore this thesis aims to assess the value and function of System 1 in everyday contexts.
This thesis used five experimental studies to investigate the use of System 1 in everyday decisions. Chapter 2 used an online experiment where participants used either System 1 or System 2 to make a choice of an app to use for a week, reporting their satisfaction with their choice both immediately and after a week of using the app. The findings showed immediate satisfaction was significantly higher for participants who made their choice quickly. Chapter 4 Experiment 1 used a longitudinal study to investigate satisfaction and happiness with career choices. Experiment 1 was underpowered, but suggested participants are not accurate at predicting what factors of choices will result in happiness over time. Chapter 4 Experiment 2 required participants to decide on a takeaway meal to order, and found that participants who reported using more intuitive System 1 decision methods experienced increased satisfaction, happiness, and positive affect about their choice both immediately and in the long term. Chapter 4 Experiment 3 replicated Experiment 2 with a choice of film to view. Experiment 3 found that increased use of System 1 processes predicted immediate satisfaction and affect about the choice, and increased happiness after viewing the film. Experiment 3 also found that those who used more System 1 during their decision making rated the film they viewed as better. Chapter 5 investigated the relationship between impulsivity, interoception, and regret with System 1 and System 2 use. Participants were asked to make a choice between snack foods in a lab experiment, and then given the opportunity to eat both their chosen snack and try the forgone option. Impulsivity was found to predict satisfaction with decisions, and strengthened the relationship between System 1 and satisfaction. Interoceptive confusion negatively predicted satisfaction, suggesting that those who are less in tune with their “gut feelings” are worse at everyday decision making. Implications for future research and decision making theory are discussed.