It’s all about the game: Infants’ action strategies during imitation are influenced by their prior expectations

It’s all about the game: Infants’ action strategies during imitation are influenced by their prior expectations Yue Yu (yy376@cornell.edu), Tamar Kushnir (tk397@cornell.edu) Department of Human Development, Cornell University Ithaca, NY 14850 USA Abstract Infants’ imitation is influenced by causal and intentional cues. Here we examine whether imitation is influenced by prior social expectations. Infants (mean age = 27 months) first played one of three games either: 1) copying the experimenters’ gestures, 2) establishing and working toward a shared goal or 3) a non-interactive control. They then participated in a separate imitation task involved both causally necessary and unnecessary actions and a goal. Infants who began by copying the experimenter were more likely to imitate causally unnecessary actions, infants who played a game with a shared goal were more likely to only perform causally necessary actions. Infants in the non-interactive control had no preferred response, and were least likely to achieve outcome as demonstrated. These results implicate the broader social context as an important factor guiding the actions infants choose to imitate, and have implications for the role of imitation in early learning. Keywords: infant; faithful imitation; emulation; prior expectation; social context; social cognition. Introduction The tendency to imitate others plays an important role in the behavioral repertoire of infants and young children. Newborns imitate facial and manual gestures as part of their earliest affiliative interactions (Meltzoff & Moore, 1977, 1989). By 6 months, infants begin to imitate sequences of object-related actions as well. Increasingly over the first few years of life, imitation becomes more than a way to affiliate with others; it becomes an important mechanism for learning about the world (Meltzoff, 1995). But infants do not always imitate faithfully. In fact, one important observation is that, in some cases, infants only copy the goals of another person’s action, ignoring the exact means of producing those goals (termed emulation , Tomasello, 1996). In other cases, infants reproduce whole action sequences faithfully (Lyons, Young, & Keil, 2007; McGuigan, Whiten, Flynn, & Horner, 2007; Nielsen & Tomaselli, 2009; Want & Harris, 2002). Studies show that which of the two behaviors – emulation or faithful imitation – infants engage in depends on several factors, including their understanding of physical causality, their ability to read intentional and pedagogical cues, and also on their assumptions that agents behave rationally in the pursuit of goals (Brugger, Lariviere, Mumme, & Bushnell, 2007; Carpenter, Call, & Tomasello, 2005; Gergely, Bekkering, & Kiraly, 2002; McGuigan & Whiten, 2009; Meltzoff, 1995). In this paper, we offer evidence of an additional factor that might drive imitative behavior, namely prior social expectations. We know from previous work that children can read and track others intentions during social interactions (Malle, Moses, Baldwin, & Bruner, 2003). These understandings could cause infants to form expectations which guide their action strategies broadly in the context of social interactions, and specifically, these expectations could result in different imitative behaviors even when controlling for other causal and intentional cues. To investigate this, we assigned groups of 27-month-old infants to play one of three games prior to participating in an imitation task. The first game involved mimicking the hand gestures of the experimenter (playing “copy me”). The second game involved taking turns finding and putting pieces in a puzzle, and thus established a shared goal. The final game was non-interactive, and served as a control. Critically, none of these games involved the toys used in the imitation task, but rather were used to establish the tenor of the overall social interaction with the experimenter. We selected a set of toys for use in the imitation test which in previous work (Brugger et al, 2007) were shown to be easy to operate and also causally transparent to infants of this age. A two action sequence was demonstrated towards toys, which led to an interesting effect. Of these two actions, the second (action B) was always necessary for producing the effect, but the first (action A) was only necessary for half of the toys. The other half of the time it was causally unnecessary. For example, in the “flowerbox”, action A was to remove a Velcro latch, and action B was to open the lid. In the Necessary condition the Velcro latch was attached on the lid and held it close, whereas in the Unnecessary condition the Velcro latch was on the other side of box and did not hold the lid close. The critical imitation task, then, occurred when action A was demonstrated but was causally unnecessary, we could see whether infants’ prior expectations would be more likely to lead to faithful imitation, emulation, or some other response. Using a similar method, Brugger et al (2007) showed that 15-month-old infants were not likely to perform the first action (action A) when it was unnecessary, despite it was part of the demonstration. Thus we could expect that, minimally (in the absence of social cues which would elicit faithful imitation), infants in our study would also likely perform only the actions necessary to produce the desired outcome. Critically, then, the ability to understand the causal properties of the toys was readily available to infants and held constant across conditions. Also held constant across conditions were the social cues during the imitation task. This was important because in previous work such cues (e.g. pedagogical intent) have been shown to influence children’s tendency to faithfully imitate (Brugger, et al, 2007; Kiraly, 2009; Lyons et al, 2007; Nielsen, 2006). In our imitation task, all demonstrated