Assessing Decision Thresholds in Primary School Students Using Signal Detection Theory: Validating an Adapted Version of the Beads Task

The decision threshold describes the minimum probability a person needs to be certain enough to make a decision. Lower decision thresholds lead people to jump to conclusions and are associated with superstitious and conspiracy-related beliefs. To shed light on the role of the decision threshold in the development of these phenomena, it is crucial to study decision thresholds at an early age. However, current measures of decision thresholds have only been administered in adult samples and are based on subjective probability estimates. The current study validates a new instrument that was adapted to measure the decision thresholds of children and is based on the objective probability values of a situation by using a signal detection analytical approach. We assessed decision thresholds in a sample of N = 299 children from an extracurricular enrichment program for talented primary school students. Receiver operating characteristic curves indicated that the new measurement instrument has high accuracy. Furthermore, its construct validity was supported by positive associations with children’s performance in the original beads task, a measure of confirmation bias, age, grade level, and math performance. However, no associations were found with a measure of alternation bias, epistemic certainty beliefs, self-concept in data-related tasks, general self-efficacy, or gender. This study introduces a new instrument for measuring the decision threshold in children using objective probability values and gives insights into decision-making processes and their implications for cognitive biases and related constructs.