Phonetic Imitation from an Individual-Difference Perspective: Subjective Attitude, Personality and ‘‘Autistic’’ Traits Alan C. L. Yu 1 *, Carissa Abrego-Collier 1 , Morgan Sonderegger 2 1 Phonology Laboratory, Department of Linguistics, University of Chicago, Chicago, Illinois, United States of America, 2 Department of Linguistics, McGill University, Montreal, Quebec, Canada Abstract Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language- external factors and a speaker’s likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual) and the outcome (positive vs. negative) of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant’s subjective attitude toward the model talker, the participant’s personality trait of openness and the autistic-like trait associated with attention switching. Citation: Yu ACL, Abrego-Collier C, Sonderegger M (2013) Phonetic Imitation from an Individual-Difference Perspective: Subjective Attitude, Personality and ‘‘Autistic’’ Traits. PLoS ONE 8(9): e74746. doi:10.1371/journal.pone.0074746 Editor: Joel Snyder, UNLV, United States of America Received February 1, 2013; Accepted August 6, 2013; Published September 30, 2013 Copyright: ß 2013 Yu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The authors have no support or funding to report. Competing Interests: The authors have declared that no competing interests exist. * E-mail: aclyu@uchicago.edu Introduction Imitation has been observed in many domains of human behavior, including postures, gestures, and facial expressions [9]. In the domain of language and speech, imitation has been observed for many properties, such as lexical and syntactic alignment [2], speech rate [3], pause and utterance duration [4], vocal intensity [5], vowel quality [6,7], and voice onset time (VOT) [8–10]. When the speech production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor, phonetic imitation or convergence obtains; phonetic divergence refers to the reverse process. For example, studies using a ‘‘shadowing’’ paradigm (e.g., [11,12]) show that subjects shift their speech production (evaluated using perceptual measures) in the direction of speech they are asked to repeat, either immediately or after a delay. Several previous studies have considered imitation of VOT in particular. A significant VOT imitation effect was reported in a single-word shadowing task using words with artificially-lengthened initial VOTs [13]. VOT imitation was also observed even when subjects were not explicitly asked to shadow: their VOTs became longer after listening to a period of speech with extended VOTs; subjects also generalized the extended VOT pattern to words they were not exposed to during the passive listening task [8,9]. Given the prevalence of imitation effects in language, some scholars have hypothesized that studies of phonetic imitation and convergence can inform the understanding of sound change. In particular, phonetic imitation found in the laboratory setting is taken to be similar to phonetic convergence in conversational interaction, which has been hypothesized as an important source of propagation of sound changes throughout speech communities [7,10,14–16]. Phonetic imitation is not an entirely automatic (i.e., it can occur without the speaker’s intention or control) or unrestricted process [9]. Contrast preservation, which has been argued to be an essential part of the phonological grammar [17–19], may constrain phonetic imitation. For example, one study found that lengthened VOTs were imitated but shortened VOTs were not [1], suggesting that speakers may not imitate if the novel phonetic feature (shortened VOT) endangers phonetic contrasts (unaspirated vs. aspirated). In the case of vowels, subjects in one study imitated only low vowels but not higher ones [6], which might be due to the influence of speaker experience; unlike the higher vowels, subjects encounter more varieties of low vowels due to differences in jaw height in accented and unaccented syllables. Beyond linguistic factors, ‘‘macro’’ socio-biological factors, such as gender/sex, have often been suggested as important moderators of imitation [1,6], although the exact nature of this modulation is not clear. Men have been found to imitate more than women in a map task [14], but less than women in a shadowing task [20]. These mixed results suggest that gender/sex may not be the appropriate predictive factor in modulating likelihood of imitation. PLOS ONE | www.plosone.org 1 September 2013 | Volume 8 | Issue 9 | e74746