For years social psychologists have exalted the power of the situation. We comfortably acknowledge that across different situations, with different people, we may act in a range of ways, or even talk using a variety of styles. Aware of this tendency, Gergen (1972) began his explorations of our shifting masks of identity. In writing letters to close friends, he realized that he came across as a "completely different person" in each letter. "In one, I was morose, pouring out a philosophy of existential sorrow; in another I was a lusty realist: in a third I was a lighthearted jokester" (p. 32). Based merely on his word choices, Gergen inadvertently varied his style to adapt to the recipients of his letters. This is a prime demonstration of our inherent knowledge of the mutability of our language with respect to varying social contexts. Intuitively when we interact with others, we adapt to them across a wide range of behaviors, especially language. When two people are talking, their communicative behaviors are patterned and coordinated, like a dance. The nonverbal literature suggests that coordination may be a fundamental aspect of human behavior; most facets of communication, such as facial expression, nonverbal vocal behavior, kinesics, visual behavior and proxemics are coordinated (Harper, Wiens, & Matarazzo, 1978) . In this article, we explore the degree to which two people in conversation coordinate by matching their word use. Linguistic research originated searching for a set of rules to combine morphemes into sentences. More recently, linguistic research has attempted to ascertain a similar syntax or grammar of conversation (Clarke, 1983) . Key to the assumption that there are rules governing all possible conversations is the definition of conversation as jointly managed (Slugoski & Hilton, 2001) . Research devoted to this subject has succeeded in uncovering structural regularities not particular to the word level: categories of speech act types such as "questions," "gives orientation," and others that neglect the nuances of actual conversation. Furthermore, they must be coded by human judges. Similar to nonverbal coordination, our definition of linguistic style matching (LSM) assumes that the words one person uses covary with those the other person uses on both a turn-by-turn level and on the broader conversational level (Cappella, 1996) . However, because the language the interactants use is coordinated and reciprocal, it is often not clear who is leading or following. We propose that the words one speaker uses prime the listener to respond in a specific way. In this fashion, an interactant is influenced by her partner's language at the word level in natural conversation in the same way one's nonverbal behavior can be influenced by another's movement (Chartrand & Bargh, 1999) . We are not proposing a temporal synchrony amongst conversants' language, yet the theoretical underpinnings of this research are undoubtedly related to the nonverbal communication's conception of synchrony. Research on synchronized interactions was strongly influenced by Condon and Ogston's (1966; McDowall, 1978) initial work on behavioral entrainment. Through sound film microanalyses of speaking and listening behavior between mothers and infants, Condon and Ogston concluded synchrony was a fundamental, universal characteristic of human communication. Condon (1982) later suggested that individual differences in synchrony could be diagnostic of psychopathology. In his original studies, an absence of synchrony was observed in people with dyslexia and other learning disabilities (Condon, 1982) . Since then, research has continued to look primarily at physical, nonverbal behavior (gestures and postural behavior), affect, attitudes, and biological rhythms. Synchrony is defined as the matching of behaviors, the adoption of similar behavioral rhythms, the manifestation of simultaneous movement and the interrelatedness of individual behaviors (Bernieri & Rosenthal, 1991) . Research has shown synchrony to be related to positive affect in interactions (Bernieri, Reznick, & Rosenthal, 1988) and interpersonal liking and smoothness of interactions (Chartrand & Bargh, 1999) . We hypothesized that interpersonal synchrony could analogously occur in a powerful form at the word level. Pennebaker and King (1999) demonstrated that the language people use to convey their thoughts and feelings is demonstrative of individual differences in selfexpression and is reliable across time and situation. Based on the idea that language provides insight into the ways individuals perceive the world, if people are matched in their linguistic styles, this would signify that they are in harmony in the ways they organize their psychological worlds. According to Byrne's (1971) similarity-liking hypothesis, this similarity in life-orientation could potentially lead to a more profound bond between them. Beyond establishing the degree of matching in word use, a second goal of the present study was to explore how it is related to the success or failure of the conversation. Many studies relevant to the present investigation have documented increased levels of attraction between unacquainted dyads that exhibit more coordination (as compared to dyads that are "not coordinated") on various nonverbal behaviorsincluding head movement, vocal activity (not verbal), facial expressions, and postural mirroring (Bernieri, Davis, Rosenthal, & Knee, 1994; Burgoon, Stern, & Dillman, 1991; Chartrand & Bargh, 1999; Hatfield, Cacioppo, & Rapson, 1994 ; for detailed reviews see Cappella, 1997) . According to the coordination-rapport hypothesis (Tickle-Degnen & Rosenthal, 1987) , attraction, satisfaction, attachment, longevity, and rapport should be positively correlated with "coordinated" interaction patterns. In theory, these findings should generalize to our own studies, leading to the prediction that LSM should correlate with liking, rapport, and social integration among the interactants. Particularly relevant to our predictions concerning LSM is Giles's Communication Accommodation Theory (CAT) . According to CAT, individuals adapt to each other's communicative behaviors to promote social approval or communication efficiency. The premise of the theory rests in individuals' ability to strategically negotiate the social distance between themselves and their interacting partners: creating, maintaining, or decreasing that distance (Shepard, Giles, & Le Poire, 2001 ). This can be done linguistically, paralinguistically, and nonverbally: for example, varying speech style, rate, pitch, or gaze. One specific strategy an individual can use is convergence, which involves modifications of accents, idioms, dialects, and Niederhoffer, Pennebaker / LINGUISTIC STYLE MATCHING 339 code-switching to become more similar to an interaction partner (see Giles & Smith, 1979 (Pennebaker, Francis, & Booth, 2001 ). LIWC analyzes one or more text files on a word-by-word basis comparing each word in a given file to 2,290 words and word stems in an internal dictionary. The words in the internal dictionary have been rated by groups of judges as representing a variety of different psychological or linguistic dimensions. The word categories include standard linguistic measures such as word count, pronouns, and articles; psychological processes, such as affective or emotional, cognitive, and sensory processes; categories that tap references to space, time, and motion; and a group of dimensions that measure a variety of personal concerns including references to sex, death, television, and occupation (for a more complete review see Pennebaker et al. It should be noted that LIWC is capable of analyzing a conversation between two people in at least three ways: all the words within the entire conversation (based on one large file); the separate language use of each interactant for the conversation (based on one file for each speaker), and language use for each person for each turn of the conversation (e.g., 50 turns in a conversation would yield 100 separate files). No studies to date have been able to quantify the degree to which word use is coordinated nor have studies shown that linguistic dimensions may be serve as the best markers of coordination. The primary goal of these studies, then, was simply to determine the psychometric properties of language in ongoing interactions. A secondary goal of the current project was to learn the degree to which LSM reflected perceptions of rapport or "clicking." If an interaction among relative strangers goes well, we might see this in the ways the two are showing comparable word use. If we detect unmatched patterns of language between two people, we might deduce conflict within the interaction. CAT might predict this is another form of convergence that leads to satisfaction and quality of communication (see Giles & Smith, 1979) . The coordination-rapport hypothesis might similarly predict LSM to signify mutual adaptation and result in positive rapport; additionally, expectancy violations theory (Burgoon, 1993) To test these ideas, we conducted three experiments analyzing the words individuals used in two-person interactions. The first two experiments were laboratory studies wherein strangers got to know one another by interacting in live computer chat rooms. The third study was an archival analysis of 15 of the original Watergate transcripts secretly recorded in the White House wherein President Richard Nixon had a series of one-on-one discussions with H. R. Haldeman, John Erlichman, or John Dean. These natural and historic interactions allowed us to compare LSM among adult speakers and, unlike the lab studies, allowed us to examine conversational leadership. Because the first two studies relied on very similar methodologies, the methods and results will be presented together before introducing the Watergate study. In the first two experiments, college students were recruited to participate in an ongoing computer-based chat interaction in laboratories in the Department of Psychology. The first experiment sought to establish the degree to which turn length and word use was related to the quality of an ongoing computerbased chat interaction between two strangers. In addition, we sought to learn if having an anonymous screen name, as is common in naturalistic Internet chat-room use, would result in different types of interactions than having a screen name identifying the interactant's real name. A total of 130 Introductory Psychology students at the University of Texas at Austin (52 men and 78 women, mean age = 20.8 years) participated in the study as part of an Introductory Psychology experimental option. Individuals were randomly assigned chat partners, resulting in 28 mixed sex, 25 all female, and 12 all male conversational dyads. Three conversations (2 all male and 1 all female dyads) were not included in the analyses due to computer errors during the study, thus resulting in 62 dyads. Niederhoffer, Pennebaker / LINGUISTIC STYLE MATCHING 341 Participants initially signed up for one of two group experiments that were scheduled at the same time in different rooms. On arrival to one of the two rooms, students were randomly directed to one of several desk computers. Unbeknownst to the participants, each computer was directly connected to a computer in the other lab. The computer pairs were connected via a private chat-room software program (available for download at http://tucows.wau.nl/circ95.html). The privately licensed chat program is a multiple application program enabling private virtual communities with live interaction. Participants were told that they would be chatting with a person on another part of campus but would not meet this person. Measures were taken to assure that participants did not see each other before the experiment began. After consenting to participate in the experiment, each participant received a brief demographic survey with 10 questions regarding levels of experience with and usage of computers and Internet chat rooms. After being logged on to their computers, half the participants were randomly assigned (on the computer screen) to enter their real name, whereas the other half were given the opportunity to invent "a screen name of their choice." Both members of each dyad were in the same real name/invented name condition. After approximately 45 minutes, participants completed the Interaction Rating Questionnaire (IRQ). This scale contains 3 items forming the "click index" as well as 12 exploratory items assessing the degree to which participants enjoyed the conversation, and various measures of their comfort level. The click index was based on the degree to which participants felt the interaction went smoothly, they felt comfortable during the interaction, and they truly got to know the other participant. After completing the questionnaire, participants were debriefed and thanked for their participation. The transcripts of the interactions were saved and ultimately printed with all identifying information removed. Independent judges rated the transcripts using a modified version of the IRQ (IRQ-Judge). The IRQ-Judge includes questions similar to the IRQ, including the same three questions forming the click index as well as items regarding the perceived levels of fluidity, liveliness, and perceived enjoyment.  Experiment 2 involved 32 (21 male, 11 female) beginning college students. Mean age was 18.2 years. Because participants were run in groups of four, speaking to each of the other three people in the group for 15 minutes each, data from a total of 48 computer chat conversations were collected. Overall, 19 interactions were mixed gender, 22 were male-male, and 7 were female-female. Data from all interactions were included in the analyses. Individuals signed up for experiments in groups of four, with the understanding that they not know any other potential participants in their time slot. On arrival at the lab, prior to any interactions, participants were escorted into separate cubicles with individual computers in a laboratory suite. Each computer was running Microsoft Chat Software (downloaded from www.microsoftchat.com), which allowed the experimenter to create separate chat rooms that only two of the participants could enter during any 15-minute interaction period. After being seated in the lab cubicles, participants were assigned an identification number as their screen name so as to prevent recognition by another participant. Each participant interacted with the other three participants for 15 minutes each. The students were individually instructed to "try to get to know the other participant." There were no limitations on conversation content. At the end of each 15-minute period, the participants completed a brief questionnaire and the experimenter reconfigured their software programs to be certain that they would be interacting with a different participant during the next 15-minute interaction period. After each conversation, participants completed a 10-item Interaction Rating Questionnaire (IRQ) (see description in Experiment 1). After the final interaction, participants were debriefed en masse, thanked, and excused. As in Experiment 1, all the transcripts of the 48 interactions were saved, and after removing any identifying information, were printed. Four independent judges rated the individual transcripts of the chatroom interactions using a modified version of the Interaction Rating Questionnaire (IRQ-Judge) (see Experiment 1). Niederhoffer, Pennebaker / LINGUISTIC STYLE MATCHING 343 The results from Experiments 1 and 2 are divided into four different categories. In the first section, we discuss the basic features of the conversations. The second section summarizes the basic psychometric properties of the self-reports and judges' ratings of interaction quality, or clicking. The next section focuses on the psychometric aspects of language. We conclude with the comparison of click ratings with the various linguistic elements hypothesized to be related to clicking.
REF found linguistic style matching both at the conversation level and locally at a turn-by-turn level in dyadic conversations.
Linguistic Style Matching In Social Interaction
Journal of Language and Social Psychology
Psychology