Fig. 1

Sketch of the experimental screen and procedure. Left: each trial started with the presentation of the value in euros and the delay in days, and the cursor was locked in the centre of the screen. To select an option, the participants navigated the cursor into the colour-coded response box in the upper right/ lower left corner. Right: in the individual condition, each participant could reach their favoured response box by executing a diagonal joystick movement. In the dyadic condition, movement directions were split up to one participant controlling the vertical movement and the other controlling the horizontal movement while ignoring the other dimension. Because both cursor movements were added, the participants were able to move the jointly controlled cursor freely on the screen, comparable to the diagonal joystick movement in the individual condition