The emergence of recursion in human language: Mentalising predicts recursive syntax task performance
Oesch N., Dunbar RIM.
© 2016 Elsevier Ltd Theory of mind, also known as mentalising, meta-representation, second-order intentionality, or mindreading is the ability to attribute and reflect on the mental states of others. A number of investigators have noted that an important relationship exists between child language development and children's understanding of second-order intentionality. However, although the ontogeny of theory of mind has been extensively studied over the past few decades, only recently have we begun to understand more concerning the limits of human mentalising ability in adults. For example, several studies have shown that the limits of mentalising ability for normal adults are consistently placed around fifth-order intentionality (i.e. I believe that you suppose that I imagine that you want me to believe that…), forming a naturally recursive hierarchy which corresponds to increasingly embedded mindreading. Moreover, several psychologists have recently suggested the adult capacity for higher-order intentionality may have played a critical role in the evolution of language, including especially the ability for recursive syntax comprehension and production, according to a cognitive bootstrapping effect. Here, we used the Imposing Memory Task (n = 210 female and 204 male adults) to analyse the association and interaction between higher-order intentionality capacity and performance on a recursive syntax measure. Multiple regression analyses indicated that recursive syntax abilities are lower than mindreading competences below fifth-order, but then reverses at higher values. In addition, a path analysis further suggested intentionality capacity as the likely causal variable. Thus, these results seem to suggest that first-order through fifth-order intentionality is necessary to assist the processing of simpler syntactic structures, but beyond fifth-order intentionality the cognitive scaffolding provided by recursive syntax may be engaged to enable higher-order mentalising. In summary, this may explain in part how and why many modern languages exhibit recursive syntax.