Words like 'this' and 'that' act as attention tools across languages

"The reason why we were interested in demonstratives is because of their connection to social cognition: demonstratives are used to direct the listener's attention to a referent and establish joint attention," says MPI's Paula Rubio-Fernández, senior investigator and co-author of the study. "Engaging in joint attention is a uniquely human capacity that links language to social cognition in communication. Because demonstratives are universal, emerged early in language evolution and are acquired early in child development, they offer an ideal test case for the interdependence between these two fundamentally human capacities."

There is debate about whether directing the listener's attention -- the 'mentalistic' representation -- is part of the meaning (semantics) of demonstratives, or whether it arises from general principles of social cognition (pragmatics). The researchers used computational modelling and experiments with speakers of ten different languages from eight different language groups to investigate this question.

In an online task, participants saw pictures of a 'speaker' requesting an object from a 'listener', who was standing on the other side of a long table. The participants were asked to take the role of the speaker, and select a demonstrative from their native language to request the object ("Now I need …"). In the pictures, the listener was either already looking at the intended object or looking at one of four other objects (closer or further from the target). If directing attention is part of the meaning of demonstratives, all speakers should be sensitive to a listener's initial attention when selecting a demonstrative. However, there should also be variation across languages.

Results showed that participants were not only sensitive to the location of the target but also to the listener's attention. As expected, the meaning of demonstratives varied within and across languages. For example, the 'near' demonstrative (such as English 'this one') sometimes had a spatial meaning ('the one close to me'). But it also had a joint attention meaning ('the one we are both looking at') or a 'mentalistic' meaning ('the one over here'), directing the listener's attention towards the speaker. Interestingly, speakers of languages with a three-word system used the medial word (such as Spanish 'ese') to indicate joint attention.

"Our work sheds light on the interface between social cognition and language. We show that representations of interlocutor attention are embedded into one of the most basic word classes that appear across all languages: demonstratives," concludes Rubio-Fernández. "Our work also shows through Bayesian computational modelling that this form of attention manipulation cannot be explained via pragmatic reasoning external to the linguistic system, suggesting that mentalistic representations are embedded in a universal component of language".