An increasing number of studies are concerned with the extent to which the vocal behavior of pairs of individuals in conversational interactions with each other shows mutual vocal coordination or entrainment. Most of these studies have involved the interactions of adults and young adults (e.g., Crown, 1991; Feldstein & Welkowitz, 1987; Field et al., 1992) and, more recently, the interactions of infants with mothers and with strangers (e.g., Beebe, Alson, Jaffe, Feldstein, & Crown, 1988; Cohn & Tronick, 1988; Jaffe, Beebe, Feldstein, Crown, & Jasnow, 2001; Jasnow & Feldstein, 1986). The study reported here examined the interactions of preadolescent dyads. The study had three major aims. The first was to determine whether, and how much, entraimnent, or what we call coordinated interpersonal timing, occurs in the dialogues of preadolescent pairs. Coordinated interpersonal timing, or CIT, refers to changes in the temporal patterns of one person in a conversation as a function of changes in those of the other pers on. The second aim was to provide descriptive statistics of the states that comprise the vocal patterning of preadolescent interactions. The last, but not at all the least aim, was to compare, in terms of the state durations and frequencies and the coefficients of CIT, the interactions of friends and acquaintances in mixed- and same-gender dyads. Thus, the study is primarily an analysis of the temporal structure of preadolescent dialogues. This information was expected to extend our knowledge of what may be the basis for subsequent differences in the social interactions of friends and acquaintances. This expectation is based upon a "dyadic systems" position which holds that the two-person group is a basic psychological unit in which personality is originally formed (Sullivan, 1947) and in which the behavior of one of the individuals is determined by the behavior of both individuals (Jaffe, Beebe, Feldstein, Crown, & Jasnow, 2001). It has been shown (Jaffe et al., 2001) that the degree to which the temporal rh ythms of mothers and their infants are coordinated not only initiates, for four-month-old infants, the formation of an adult dialogue structure prelinguistically, but predicts the quality of the mother-infant relationship that will have developed by age 12 months.
The few investigations that have examined the chronography of children's interactions were concerned with whether the conversational time patterns of the children exhibited CIT, as well as the effects of age, gender, and ethnicity on the conversational time patterns of the children. One study (Welkowitz, Bond, & Feldstein, 1984a) of Hawaiian children found that the vocal time patterns are stable indices of children's conversational behavior, and that the patterns seem to vary as a function of the gender and ethnicity of the conversational pairs. Another study (Welkowitz, Bond, & Feldstein, 1984b) of Japanese-American children and adults in mixed- and same-gender pairs found gender effects for the adults but not for the children. Two earlier studies (Garvey & BenDebba, 1974; Welkowitz, Cariffe, & Feldstein, 1976) seemed to indicate that the development of CIT is positively related to age. However, none of these studies involved preadolescents, and the techniques for assessing CIT were relatively crude. In the present study, CIT was estimated by the use of time-series regression analyses.
The 30 female and 26 male pre- and early adolescents who participated in the study were recruited from two sixth-grade classes at the West Laboratory Elementary School for a study by Field et al. (1992). The average age of the participants was 11.5 years, and the friends knew each other for an average of 4.2 years. The acquaintances knew each other for approximately five months. The selection of friends and acquaintances was made on the basis of a sociogram that presented cartoon faces with messages in balloon-like clouds coming from the cartoon faces such as "I know ______ the best" and "I know ______ the least. …