Understanding the value of telescopic testimony: With age, a predominantly White Midwestern sample of children credits knowledge to speakers whose statements go beyond the evidence.

One primary value of testimony lies in its ability to extend our powers of observation. Do children credit more knowledge to speakers whose testimony goes beyond firsthand observation? The current study investigated 3- to 8-year-old children's (N = 180) and adults' (N = 20) knowledge attributions to speakers who made claims regarding perceptually evident features of a novel animal (e.g., "is brown") or claims regarding perceptually absent features (e.g., "eats insects"). By 7 years of age, children and adults attributed more knowledge to speakers who discussed telescopic information and generalized their knowledge to other domains. Because the knowledge base of child listeners expands with age, they place increased value on telescopic information and the speakers who provide it.

Evaluations of epistemic and practical reasons for belief in a predominantly White U.S. sample of preschoolers.

Parents and educators commonly seek to influence children's behavior by providing them with practical incentives, but how should we understand the influence of such incentives on children's beliefs? Are children capable of distinguishing between speech acts that provide practical reasons for believing, such as requests and offers, from speech acts that provide straightforward epistemic reasons, such as simple acts of telling? To investigate these questions, we randomly assigned 3- to 6-year-old children (N = 97) to one of two conditions (Request or Offer) in which two speakers each commented on a series of four exotic animals. In each condition, an agent who stated what an object was called with a simple telling ("This is a tanzer") was contrasted with an agent who made either a doxastic request ("I want you to think that this is a tanzer") or a doxastic offer ("If you think that this is a tanzer, I'll let you play with this new toy"). We then measured children's endorsement of and semantic memory for the claims as well as their knowledge attributions and resource allocation decisions. Our results suggest that children appreciate the epistemic reasons inherent in acts of telling when contrasted with doxastic requests, as evidenced by their general preference to learn from, attribute knowledge to, and share with the teller in the Request condition. When tellings were contrasted with doxastic offers, children were less systematic in their preferences. We discuss various interpretations of this finding and offer suggestions for future research.

Reasoning about knowledge: Children's evaluations of generality and verifiability.

In a series of experiments, we examined 3- to 8-year-old children's (N=223) and adults' (N=32) use of two properties of testimony to estimate a speaker's knowledge: generality and verifiability. Participants were presented with a "Generic speaker" who made a series of 4 general claims about "pangolins" (a novel animal kind), and a "Specific speaker" who made a series of 4 specific claims about "this pangolin" as an individual. To investigate the role of verifiability, we systematically varied whether the claim referred to a perceptually-obvious feature visible in a picture (e.g., "has a pointy nose") or a non-evident feature that was not visible (e.g., "sleeps in a hollow tree"). Three main findings emerged: (1) young children showed a pronounced reliance on verifiability that decreased with age. Three-year-old children were especially prone to credit knowledge to speakers who made verifiable claims, whereas 7- to 8-year-olds and adults credited knowledge to generic speakers regardless of whether the claims were verifiable; (2) children's attributions of knowledge to generic speakers was not detectable until age 5, and only when those claims were also verifiable; (3) children often generalized speakers' knowledge outside of the pangolin domain, indicating a belief that a person's knowledge about pangolins likely extends to new facts. Findings indicate that young children may be inclined to doubt speakers who make claims they cannot verify themselves, as well as a developmentally increasing appreciation for speakers who make general claims.