Utilizing probabilities as decision weights in closed and open information boards: A comparison of children and adults

• 10 year olds but not 6 year olds systematically use probabilities as decision weights.
• Presentation format matters: probability weighting increases in an open board.
• Intrusion effects: irrelevant information biases decisions in an open board.
• Holistic processing: children and adults attend to information patterns.
• Processing potentials: 10 year olds and adults do not differ in integration capability.

Decisions in preschoolers (6 years), elementary schoolers (9.7 years), and adults (21 years) were studied with an information board crossing three probabilistic cues (validities: .83, .67, .50) with two options. Experiment 1 (n = 215) applied a standard version of the information board (closed presentation format), in which information must be searched sequentially and kept in mind for the decision. Experiment 2 (n = 217) applied an open format (Glöckner & Betsch, 2008), in which all information was visible during decision making. Elementary schoolers but not preschoolers benefited from an open format — indicated by an increase in using probabilities as decision weights. In the open but not closed format, choices were biased by normatively irrelevant information (the lure). Variations in the prediction patterns of the cues influenced decisions in all age groups. Effects for presentation format, pattern, and lure jointly indicate that even children are capable of considering multiple information in their decisions.