What’s the Evidence Say? The Relation Between Evidential-Trust and Theory of Mind

ABSTRACT

Previous research has shown that linguistic cues such as mental and modal verbs can influence young children’s judgments about the reliability of informants. Further, certain languages include grammatical morphemes (i.e. evidential markers), which clarify the source of information coming from testimony (e.g., Bulgarian, Japanese, Turkish). Accordingly, the first aim of the current study is to examine whether Turkish-speaking children’s reliability judgments change based on evidential markers (i.e. the past-tense direct evidential marker, –DI, and the past-tense indirect evidential marker, –mIş). The literature has also investigated whether selective trust abilities are related to understanding the epistemic states of others (i.e., Theory of Mind). Therefore, the second aim is to examine the relation between selective trust based on evidential markers and ToM abilities by including a comprehensive ToM battery. Eighty-six Turkish-speaking preschool and elementary school children between the ages of 4 and 7, residing in a metropolitan city in Turkey, participated in a selective trust task based on evidential markers, a general language task, and a ToM battery. The results of the current study showed that after the age of 6, Turkish-speaking children start to selectively trust the informant using the past-tense direct evidential marker, –DI, over the past-tense indirect evidential marker, –mIş. Selective trust performance was related to receptive vocabulary but not to ToM abilities after controlling for participant gender and age. Overall, the results contribute to current discussions about children’s selective trust ability based on linguistic cues and its relation with ToM.

KEYWORDS:

• selective trust
• theory of mind
• evidential markers
• reliability
• Turkish

Acknowledgments

We would like to thank all of children and their parents who participated in this study as well as the preschools for helping with data collection. We would like to also thank the anonymous reviewers for helpful comments and feedback. Lastly, many thanks to research assistants for their help conducting the study.

Authorship

Note that the first authorship is shared by B. Çelik. and N. Ergut. Data collection and data analyses were performed by B. Çelik and N. Ergut under the supervision of J.W.P Allen. All authors wrote the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

Data can be made available on request.

Notes

¹ There is also another evidential marker (–DIR) used for the present tense and allows speakers to make a logical deduction about facts and regularities (for more on the types of evidential markers in Turkish, see Aksu-Koç, Ögel-Balaban, & Alp, 2009).

² Note that the appearance-reality task was excluded from all analyses. See ToM results section for details.

³ Two additional conditions were piloted for a second study in which the direct evidential marker was pitted against the indirect marker with a source (e.g., “best friend”). Both of these conditions were conducted after the current trust task was completed.

⁴ Eighty college-aged adults also participated in the evidential-trust task in a survey format. The findings revealed that adults significantly preferred the direct evidential informant using, –DI over the indirect evidential informant using, –mIş, t(79) = 10.548, p < 0.001 (i.e., in accordance with expectations, adults found the informant with the direct evidential marker, –DI more reliable than the informant with the indirect evidential marker, –mIş).