Table 1. Description of the 5 RIG tasks used in the experiment.

Order was fixed across participants.

Task	Description
Tossing a coin	Participants had to create a series of 12 head-or-tails that would “look random to somebody else” by clicking on one of the two sides of a coin appearing on the screen. The resulting series was not visible on the screen (the participant could only see the last choice made).
Guessing a card	Participants had to select one of 5 types of cards (Zener cards; see e.g. [45]), ten times. In contrast to the other tasks, they were not asked to make the result look random. Instead, they were asked to guess which card will appear after a random shuffle.
Rolling a die	Participants had to generate a string of 10 numbers between 1 and 6, as random as possible (“the kind of sequence you’d get if you really rolled a die”). In contrast to the preceding cases, they could here see all previous choices, but could not change any of them.
Pointing to circles	Participants had to point 10 times at one out of 9 circles displayed simultaneously on the screen. They could not see their previous choices. This task is an adaptation of the classical Mittenecker pointing test [13].
Filling a grid	Participants had to blacken cells in a 3x3 grid such that the result would look randomly patterned, starting from a white grid. In contrast to the other tasks, they could see their choice and click as many times as they wished. Clicking on a white cell made it black, and vice versa.