Fig. 1.
The card gambling task. Figure adapted with permission from Macoveanu and colleagues.16 (A) All trials had 3 phases: information, choice and outcome. During the information phase, participants were informed about the sum of money they had accumulated and the bet size (3, 4 or 5 Danish kroner [DKK]), which could be lost. In the choice phase, 2 sets of cards were presented together with the associated monetary reward. Participants chose the set of cards in which they believed the ace of hearts would be hidden. In the outcome phase, the ace of hearts was revealed, providing the participants with feedback on whether they chose the right set and whether they won the associated reward or lost the bet. (B) The 6 possible choices with associated winning amounts in DKK. (C) Risk choice behaviour during the gambling task. The panel shows the distribution of the 6 risk choices across the high-risk twins and low-risk twins. Choices are paired according to the 3 trial types, with the dark shade representing choices with winning odds less than 50% and the light shade representing choices with winning odds greater than 50%.