Adjusting linguistically to others: the role of social context In lexical choices and spatial language

The human brain is highly sensitive to social information and so is our language production system: people adjust not just what they say but also how they say it in response to the social context. For instance, we are sensitive to the presence of others, and our interactional expectations and goals affect how we individually choose to talk about and refer to things. This thesis is an investigation of the social factors that might lead speakers to adapt linguistically to others. The question of linguistic adaptation is conceived and addressed at two levels: as lexical convergence (i.e., interlocutors coordinating their lexical choices with each other), and as spatial perspective taking in language use (i.e., speakers abandoning their self perspective in favour of another's when verbally locating objects in space). What motivated my research was two-fold. First, I aimed to contribute to the understanding of the interplay between the automatic cognitive accounts and the strategic social accounts of linguistic convergence. At the same time, I wanted to explore new analytical tools for the investigation of interpersonal coordination in conversation (cross-recurrence quantification analysis (CRQA)). Second, there are conflicting explanations as to why people often abandon their self spatial perspective when another person is present in the environment. I aimed to clarify this by bringing together insights from different research fields: spatial language production, spatial cognition, joint attention and joint action. A first set of experiments investigated the effects of speakers' deceptive goals on lexical convergence. Given the extensive evidence that one interlocutor's choices of words shapes another's during collaborative interaction, would we still observe this coordination of linguistic behaviour under conditions of no coordination of intents? In two novel interactive priming paradigms, half of the participants deceived their naive partner in a detective game (Experiment 1) or a picture naming/matching task (Experiment 2-3) in order to jeopardise their partner's performance in resolving the crime or in a related memory task. Crucially, participants were primed by their partner with suitable-yet-unusual names for objects. I did not find any consistent evidence that deceiving led to a different degree of lexical convergence between deceivers and deceived than between truthful interlocutors. I then explored possibilities and challenges of the use of cross-recurrence quantification analysis (CRQA) (a new analytical tool borrowed from dynamical systems) for the study of lexical convergence in conversation. I applied CRQA in Experiment 4, where I focused on the strategic social accounts of linguistic convergence and investigated whether speakers' tendency to match their interlocutors' lexical choices depended on the social impression that they formed of each other in a previous interaction, and whether this tendency was further modulated by the interactional goal. I developed a novel two-stage paradigm: pairs of participants first experienced a collectivist or an individualistic co-player in an economic decision game (in reality, a pre-set computer programme) and then engaged in a discussion of a survival scenario (this time with the real other) divided in an open-ended vs. joint-goal driven part. I found no evidence that the social impression of their interlocutor affected speakers' degree of lexical convergence. Greater convergence was observed in the joint-goal dialogues, replicating previous findings at syntactic level. Experiments 5-7 left the interactive framework of the previous two sets of experiments and explored spatial perspective taking in a non-interactive language task. I investigated why the presence of a person in the environment can induce speakers to abandon their self perspective to locate objects: Do speakers adapt their spatial descriptions to the vantage point of the person out of intentionality-mediated simulation or of general attention-orienting mechanisms? In an online paradigm, participants located objects in photographs that sometimes contained a person or a plant in various positions with respect to the to-be-located object. Findings were consistent with the simulated intentional accounts and linked non-self spatial perspective in language to the apprehension of another person’s visual affordance. Experiments 8-9 investigated the role of shared experience on perspective taking in spatial language. Prior to any communicative and interactional demand, do speakers adapt their spatial descriptions to the presumed perspective of someone who is attending to the same environment at the same time as them? And is this tendency further affected by the number of co-attendees? I expanded the previous online paradigm and induced participants into thinking that someone else was doing the task at the same time as them. I found that shared experience reinforced self perspective (via shared perspective) rather than reinforcing non-self perspective (via unshared perspective). I did not find any crowd effect.