Effects of social skills on lexical alignment in human-human interaction and human-computer interaction

Over the past decade, people's language behaviors towards computer partners have been capturing growing interests with the prevalence of interaction with dialogue systems. However, it remains controversial whether people perceive and respond to computer and human partners in the same way. To address this issue, the current study investigated whether speakers converge with their conversational partner on lexical choices (i.e., lexical alignment) to the same extent when they believed the partner was a human (i.e., human-human interaction, HHI) and when they believed the partner was a computer (i.e., human-computer interaction, HCI), and whether the strength of lexical alignment is moderated by individuals' social skills in the same fashion in HHI and HCI. A speech-based picture naming and matching task was adopted to measure participants' lexical alignment towards their conversational partner while participants' social skills were assessed by using the Chinese Universitystudents Social Skill Inventory (ChUSSI). Results indicated that lexical alignment in HCI was stronger than that in HHI (79.5% vs. 58.6%). In addition, participants' social skills score, in particular the score on protecting Partner's Mianzi (i.e., dignity and prestige) in the ChUSSI significantly predicted participants' propensity of lexical alignment in HHI but didn't in HCI. More specifically, participants who were evaluated to be more concerned with others' social standing were significantly more likely to align with their partner in the HHI context (8 = 0.896, Z = 2.847, p < 0.001), but this correlation did not hold in HCI (8 = -0.333, Z = -1.241, p = 0.214). These findings shed light on the potential boundary between speakers' representations of human and computer interlocutors.