2018 Sat Session B 1415

Saturday, November 3, 2018 | Session B, Conference Auditorium | 2:15pm

Beyond words: Children apply the principle of informativeness to non-linguistic symbols
A. Kampa, A. Papafragou

A foundational principle of communication is that speakers should offer as much information as required during conversation.(1,2) When a speaker offers a weak statement (“Some ladybugs have spots”), the listener often infers that the speaker doesn’t know whether a stronger statement (“All ladybugs have spots”) is true,(3,4) since a fully knowledgeable speaker should provide fully informative statements. Classic theories of communication assume that the principle of informativeness extends beyond linguistic interactions,(1,2) but relevant evidence so far is limited.(5,6) Thus we ask whether 4- and 5-year-olds expect drawings to be informative in accord with the creator’s knowledge.(7) We adopt a simple paradigm(8) in which 4- and 5-year-olds can successfully link scalar utterances to speaker knowledge and extend it to non-linguistic representations.

In Experiment 1, 4-year-olds, 5-year-olds, and adults (N=25 per group) saw a pair of photos depicting a girl (“Danielle”) facing the participant behind a two-compartment box (Fig.1). In one photo, Danielle and the participant had full visual access to both compartments of the box (full knowledge). In the other, the participant had full access, but Danielle could only see one compartment (limited knowledge). Participants were told that Danielle would look at each box, then draw what she sees in one of them. A new photo showed Danielle’s drawing that either depicted both objects (Strong) or only one object (Weak; Fig.2). Participants were asked to select which box she drew. There were 8 trials (4 Strong, 4 Weak; mixed). A pragmatic responder should link the strong drawing to the full-access box (and the full-knowledge agent) and the weak drawing to the limited-access box (and the limited-knowledge agent), in accordance with relative levels of informativeness. A logistic mixed effects model predicting accuracy with Trial (Strong, Weak) and Age (Adults, 5s, 4s) as fixed predictors (random effects included intercepts for subjects and items and a slope for Trial per subject) revealed an effect of Age: adults performed better than children (β=-1.6094, p=.008), but 4s and 5s did not differ (p=.24). Children’s performance was not different from chance on weak trials (Table 1).

To test whether the detail in the drawings impeded their symbolic function,(9,10) Exp.2 modified Exp.1 by using schematic drawings (Fig.2, N=25 per group). Results replicated the Age effect of Exp.1 (Table 1). However, comparisons across experiments revealed that participants performed better in Exp.2 than Exp.1 (β=-1.6022, z=-2.284, p=.022). Unsurprisingly, adults performed better than children overall (β=-1.6022, z=-3.752, p<.001), but 5-year-olds performed better than 4-year-olds (β=1.2361, z=2.773, p=.006). In Exp.2, performance differed from chance except for weak trials in the youngest group.

We conclude that the principle of informativeness extends to non-linguistic symbols: 5- year-olds and adults expect drawings, like utterances, to be informative in accordance with the creator’s knowledge. However, the drawings’ visual detail affects their success. Furthermore, 4- year-olds do not successfully link incomplete drawings to partial knowledge. Given that under similar conditions 4-year-olds can use weak utterances to infer lack of speaker knowledge,(9) we attribute their present failure to the developing understanding of the symbolic (and selective) representational function of drawings.

References
1) Grice, P. (1989). Studies in the way of words. Cambridge, MA: Harvard University Press. 2) Sperber, D., & Wilson, D. (1986). Relevance: Communication and cognition. Cambridge, MA: Harvard University Press. 2nd ed. 1995. 3) Bergen, L., & Grodner, D. J. (2012). Speaker knowledge influences the comprehension of pragmatic inferences. JEP: LMC, 38, 1450. 4) Breheny, R., Ferguson, H., & Katsos, N. (2013). Taking the epistemic step. Cognition, 126, 423-440. 5) Papafragou, A., Friedberg, C., & Cohen, M. (in press). The role of speaker knowledge in children’s pragmatic inferences. Child Development. 6) Gweon, H., Pelton, H., Konopka, J. A., & Schulz, L. E. (2014). Sins of omission: Children selectively explore when teachers are under-informative. Cognition, 132(3), 335-341. 7) Allen, M. L., Bloom, P., & Hodgson, E. (2010). Do young children know what makes a picture useful to other people? Journal of Cognition and Culture, 10(1), 27-37. 8) Kampa, A., & Papafragou, A. (2017). Gricean epistemic reasoning in 4-year-olds. Proceedings from the 39th Annual Meeting of the Cognitive Science Society. 9) DeLoache, 341 S. (2000). Dual representation and young children’s use of scale models. Child Development, 71(2), 329-338. 10) Uttal, D. H., O’Doherty, K., Newland, R., Hand, L. L., & DeLoache, J. (2009). Dual representation and the linking of concrete and symbolic representations. Child Development Perspectives, 3(3), 156-159. 11) Hochstein, L., Bale, A., Fox, D., & Barner, D. (2016). Ignorance and Inference. Journal of Semantics, 33, 107-135.