The more random people's preference judgments are, the more they explore in gambling tasks.

Background: The decision-making process has been investigated separately in the context of externally guided decision-making (EDM, e.g., a gambling task) and internally guided decision-making (IDM, e.g., a preference judgment). In EDM situations, a predictable correct answer exists, and the value of the chosen item increases when positive feedback is received. On the contrary, in IDM situations, there is no objectively correct answer, and participants must decide based on their own internal criteria, such as preference or belief. In IDM, a choice-induced preference change occurs when the value of the chosen item increases and that of the rejected item decreases. However, since these two types of decision-making have been investigated separately, their relationship remains unclear.

Methods: The present study examined the consistency in an individual's tendency of decision-making reflected in the model parameters (i.e., learning rate and inverse temperature) between EDM and IDM. In this study, participants performed EDM and IDM tasks with different items.

Results: The findings indicated that an individual's tendency with respect to how much value is reflected in decision-making (i.e., inverse temperature) between EDM and IDM is consistent. By contrast, no such consistency was observed for the degree of value change after a decision (i.e., the learning rate).

Conclusions: This study demonstrates the close relationship between these two types of decision-making and offers a more comprehensive understanding of the human decision-making process.