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.

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.