Learning frequently forces us to rely on the good judgment and epistemic vigilance of sources with no more firsthand knowledge of a topic than ourselves, but who may have more second or third- hand knowledge. Yet, being forced to rely on their judgment doesn’t prevent us from evaluating their judgment: one might trust information because it was passed on to you by someone whose epistemic vigilance you trust, but reject it from someone whom you believe lacks good judgment. We present two experiments suggest that by integrating affective cues like anger and surprise along with perceptual access and consensus, children infer what others believe and what the correct answer to a question is. We discuss implications for consensus-based social learning strategies.

Communication in groups allows social learners to influence one another and change their beliefs over time. Though some of the same heuristics that guide learners’ trust in individual informants can be applied to groups, variation in how individual beliefs are aggregated into a collective judgement can radically alter the accuracy of collective judgement. How do observers evaluate collective judgements? We present two experiments testing the impact of affective signals on observer trust. In each experiment, one faction “converts” group members from an opposing faction, or is converted by them. When the focal faction is surprised at the opposing view, observer trust in the focal faction’s belief rises or falls as consensus increases or decreases. When the focal faction is angry, observer trust falls when consensus decreases, but does not rise even when the “consensus” approaches unanimity. Affective signals in group interactions may help naive learners evaluate collective accuracy.

Psychologists frequently use response time to study cognitive processes, but response time may also be a part of the commonsense psychology that allows us to make inferences about other agents’ mental processes. We present evidence that by age six, children expect that solutions to a complex problem can be produced quickly if already memorized, but not if they need to be solved for the first time. We suggest that children could use response times to evaluate agents’ competence and expertise, as well as to assess the value and relevance of information.

Learners faced with competing statements that each have support from multiple sources must decide whom to trust. Lacking firsthand knowledge, they frequently trust the majority. Yet, majorities can be misleading if most members are relying on hearsay from just a few members with firsthand knowledge. Thus, past work has emphasized the importance of informational independence when deciding whom to trust, showing that children and adults do consider informational independence important in certain contexts. However, because informational independence precludes group deliberation, we ask whether children make the reverse inference and devalue informational independence when facing a problem that could benefit from deliberation. In two studies, children and adults ignore informational independence when attempting to answer abstract reasoning questions. However, for a question type for which deliberative reasoning would be of doubtful benefit, children and adults seek advice from multiple independent sources rather than a deliberative group.

People make sense of each others behavior by assuming that beliefs and desires vary across agents. We propose thatpeople are more conservative when it comes to risk: when an agent takes an extreme risk, we assume they have privilegedinformation rather than high risk tolerance. Participants watched an agent choose either to obtain three guaranteed tokens,or guess which box from a set had four tokens. After watching the agents choice, participants played the game themselves.In Study 1, participants were quicker to imitate an agent who immediately made extremely risky bets than one whostarted out making low-risk bets that became progressively riskier, suggesting that they inferred that risk-seeking agentswere knowledgeable. In Study 2, participants ceased taking risky bets when the anonymous agent did, suggesting thatparticipants choices depend on mental state inferences rather than contagious but mind-blind risk-seeking behavior.

We suggest that some of the mechanisms underlying network effects on cultural evolution are intuitively accessible to laypeople, and may be part of the suite of social learning strategies underlying the human capacity for cumulative culture. Interest in the psychological mechanisms underlying this capacity typically focuses on learners’ ability to identify reliable sources and capacity for high-fidelity imitation. Yet, at the population level, research suggests that network structures themselves may influence cumulative learning by changing individuals’ explore-exploit patterns. In our experiments, adults infer that more proximal or distal clusters in a fragmented network will have more similar or dissimilar technological “styles”, and prefer to seek advice from more distant experts when asked to innovate, but more proximate experts when asked to remember. Commonsense intuitions about how social networks shape our access to information and diversity- fidelity tradeoffs for memory and innovation may make us more effective social learners.

Consensus-based social learning strategies often outcompete other strategies in evolutionary models. But while formal proofs suggest that consensus’ reliability is compromised when individual judgments are not independent, this makes for a notoriously implausible assumption in the biological world: the people we learn from are constantly learning from each other as well. How do we avoid being misled by consensus? We present two experiments and a computational model examining commonsense reasoning about how people’s public and private judgments are influenced by the consensus and social status of those around them. Results suggest that while people realize that these two factors can cause others’ public and private judgments to diverge, their own trust in public consensus depends on how accurately they believe it reflects their informants’ true beliefs.

Collaboration can make collective judgments more accurate than individual judgments, but it also comes with costs in time, effort, and social cohesion. But how do we estimate these costs? In two experiments, we introduce children and adults to two teams in which the teammates disagree about the optimal solution to a novel problem, and ask which team would need more time to reach a consensus decision. We find that all ages expect slower decisions from teams with more people or factions, and expect the number of factions to matter more than the number of people. But only adults expect decisions initially endorsed by a stronger faction to be faster than those endorsed by a weaker faction. Results are discussed in context of children’s reasoning about dominance, and models of time-rational collective decision-making.