Can Children and Adults Balance Majority Size with Information Quality in Learning from Preferences?

We investigate how 3- to 5-year-old US and Canadian children (N = 189) and US adults (N = 241) balance the number of endorsements for a given option with the quality of the informants’ source of information when deciding which of two boxes contains the better option. When choosing between two different boxes endorsed by groups of equal sizes, both children (Experiments 1–3) and adults (Experiment 6) tend to choose boxes endorsed by informants with visual access to the boxes over informants with hearsay. However, children’s choices were biased towards the larger group when the size of the group conflicted with the quality of the source of the groups’ information (Experiments 4–5), while adults more often chose the option endorsed by the group with the higher quality information (Experiment 6). Children were more likely to conform to a majority opinion when compared to both adults and to a normative computational model that endorses a group proportional to the number of independent, direct observations made by that group’s informants. These findings suggest that, while adults balance the size of a majority with the quality of the informants’ information source, preschoolers can evaluate when groups differ in the source of their information, but may assume that the presence of a majority endorsing an option is inherently informative over and above the information source group members’ testimony relied on.