2.2.4. Three-Item Cognitive Reflection Test

After having completed the above-mentioned tasks, the subjects proceed to the three-item CRT [5]. The three-item CRT can be found in Appendix B.

The test is used to detect an individual's proclivity for applying two systems of decision-making: System 1 and System 2 processes [19]. System 1 is the intuitive "part" of the brain that relies on heuristics and automaticity. It possesses no computational capacity and is characterized as unconscious. It is fast, automatic and requires no effort. System 2 is the more analytical and rational system. It is deliberate and activated when facing complex calculations, different choices and requires the individual to be focused [20]. The performance on CRT indicates whether an individual is able to overcome the desire to go with the intuitive (incorrect) answer, reflect further upon the question and reach the, when explained to, relatively easy correct answer. For example the first question of the CRT: *A bat and*

<sup>1</sup> The experimental design applied actual matching on the subset of subjects who gave DKK 0 in the *dictator game*. Ex ante it could be expected that at least one subject would do so, based on previous *dictator game* experiments (In a meta study [18] found that 36.11% of all participants chose to give nothing).

*a ball cost \$1.10. The bat costs \$1.00 more than the ball. How much does the ball cost? \_\_\_ cents. Intuitive Answer: 10 / Correct Answer: 5.*

Based on the answers to the CRT I divide subjects into three groups using the categorization used by [21]: Subjects who answered correctly two or more items on the CRT are categorized as *reflective*. Those opting for the intuitive, but wrong answer at least in two of the three items are *intuitive*. The subjects who are not categorized as either *reflective* or *intuitive*, form the residual group. For precise details of the categorization, see Appendix C.
