‘Broccoli is candy’: the role of metaphors in children’s persuasive communication

Persuasion is a complex communicative process aiming at influencing others’ beliefs or behaviors. Imbuing everyday communication, persuasion is a crucial skill for children to manage social interactions successfully. While theoretically persuasion has been linked with the mastery of figurative language and with pragmatics more broadly, there is a scarcity of empirical evidence exploring the relationship between persuasion and metaphor skills. Here we tackle this issue in early childhood by examining whether individual differences in metaphor skills are related to those in persuasion. A sample of 167 children (age 4-6 years) was assessed for persuasive abilities alongside metaphor comprehension and production, in addition to vocabulary and working memory skills as control variables. Results showed an improvement in persuasive skills at 5 years of age. Across ages, children preferred to use positive persuasive strategies (i.e., offering rewards) over negative ones (i.e., punishments), while psychological strategies relying on mitigation and modeling were rarely used. Regardless of the type of strategy, persuasion correlated positively with vocabulary skills. Interestingly, greater use of psychological persuasive strategies was associated with better metaphor production skills (being conversely hampered by working memory), while no effect of metaphor comprehension was found. Overall, these findings suggest that some aspects of metaphor skills, within the broader set of pragmatic competencies, might be a driving factor in achieving a high-level persuasive style. Such aspects possibly deal with the functions of metaphors to favor flexible conceptualization and social use of language.