A defining characteristic of human social life is cooperation. Human beings cooperate with one another in a much wider range of contexts and in much more complex ways than do other primate species (Richerson and Boyd
2005). A recent theoretical proposal suggested that the need to participate with others in cooperative activities with shared goals and shared intentions (shared intentionality) may have been the driving force in human evolution leading to all kinds of supporting social-cognitive skills such as complex mind-reading, joint attention, and cooperative communication (Tomasello et al.
2005). Ontogenetically, skills of shared intentionality emerge soon after infants’ first birthday. They develop the capacity to
understand others’ individual goals and intentions. In addition, at around this same age they also develop the skills and motivation to
share goals and intentions with others. The ability to share goals and intentions is of crucial importance as it structures the way infants attend jointly to things with other persons and the way they interact with and imitate others who are attempting to show them how to do things (Tomasello et al.
2005).
Helping and Cooperation
Helping behaviors demonstrate that children understand others’ goals; one person struggles to achieve a goal and the child spontaneously assists, showing recognition of that person’s individual goal as well as a motivation to contribute to goal achievement. It is well known that young children show empathy for other persons and prosocially help them to achieve their goals from fairly early in the preschool years (see Eisenberg and Fabes
1998, for a review). In a recent study, Warneken and Tomasello (
2006) found that even 18-month-old infants spontaneously helped an adult when he, for example, dropped an object accidentally (as opposed to threw it away on purpose) or was struggling to open a cabinet (see also Kuhlmeier et al.
2003; Liszkowski et al.
2006). These results demonstrate that even pre- or just linguistic infants: (1) understand the actor’s individual goal, and (2) are motivated to help.
Full-fledged cooperation involves activities with shared goals and shared intentions. Following Bratman (
1992), shared cooperative activities have three main features (slightly modified): (1) the cooperating partners are mutually responsive to each other, (2) they have a shared goal, (3) and they mutually support each other in their roles in order to achieve that shared goal. It was previously believed that only older children engage in full-fledged cooperative activities. Ashley and Tomasello (
1998) presented 2- and 3-year-old dyads of peers with a clear tube with a toy inside; to get the toy one child had to pull a string to bring it in front of a door at the same time that the other child operated a lever to open the door. Children were over 3 years old before they could coordinate their behavior and attention skillfully and communicate effectively with one another in this difficult task. Brownell and Carriger (
1990,
1991) presented pairs of young children with a task in which one child had to manipulate a spring-loaded handle to bring a toy in front of an opening, and the other child had simply to grab it. Only children at 24 months of age and older were able to coordinate their behavior and attention successfully and repeatedly with a peer.
Recently, Warneken et al. (
2006) addressed the question whether even younger infants are successful when they cooperate with a more skillful adult partner compared to studies using peer dyads. They presented 18- and 24-month-old infants with different nonverbal cooperative tasks, i.e., successful task mastery did not require verbal communication. They measured the infants’ behaviors depending on the pre-programmed behaviors of the adult. The crucial manipulation was that the experimenter stopped carrying out his role at certain moments in the shared activity (see Ross and Lollis
1987, for the original use of this method). The key question in this manipulation were the infants’ responses to the interruption: would they attempt to re-engage the adult in the pursuit of their common goal, or simply continue attempting to solve the problem alone? Results showed that virtually all infants at 18 and 24 months engaged in the cooperative tasks, and moreover, all infants produced at least one communicative attempt aimed at re-engaging the adult during the interruptions. These results suggest that even before the second birthday, typically developing infants are capable of forming a shared goal and then coordinating their behavior and attention with an adult in pursuit of this common purpose (Warneken et al.
2006).
Autism
Autism is a neurobiological disorder that is diagnosed by three areas of behavior: (1) impairments in social behavior, (2) deficits in communication and language, and (3) restricted and repetitive behaviors and/or interests (American Psychiatric Association
1994). Autism is present early, with symptoms generally manifest in the first two years of life. While social functioning is severely affected, not all aspects of social behavior are equally impaired in autism. For instance, attachment behavior does not appear to be uniquely impaired in autism, as demonstrated in a series of surprising findings in the 1990s (e.g., Capps et al.
1994; Rogers et al.
1993). Moreover, in social interactions with others, children with autism respond appropriately to social engagement from their parents (Kasari et al.
1993). Furthermore, at least two different groups have shown that children with autism appear to understand other people’s intentions regarding actions on objects (Aldridge et al.
2000; Carpenter et al.
2001). These authors based their conclusions on the performance of children with autism in Meltzoff’s (
1995) Behavioral Re-enactment Procedure, in which the experimenter tried but failed to perform an action on an object. Surprisingly, children with autism, rather than merely copied the precise act of the model, performed his/her intended action. These findings suggest that children with autism are not completely blind to others’ minds, but they can “read” the meaning of others’ overt behaviors even when it involves intended but unperformed acts on objects. In addition to “reading” intentions regarding actions on objects, children with autism in group studies appear to have some knowledge of what others see (Leekam et al.
1997) or, in some cases, to what others know (Baron-Cohen
1995) regarding objects. Thus, children with autism seem to understand something about other people’s actions in terms of individual intentionality, such as their individual perceptions and intentions.
On the other hand, there are striking social impairments that are widely described in the autism literature and that might as well be crucial skills in order to cooperate with others. The imitation deficit is particularly well documented in autism (e.g., Charman et al.
1997; Rogers and Pennington
1991; Rogers
1999; Sigman and Ungerer
1984; Smith and Bryson
1998; Stone et al.
1997; Williams et al.
2004). Because of the pivotal role of imitation in the development of more mature socio-emotional skills (e.g., Meltzoff
1990; Rogers
1999; Rogers and Pennington
1991; Stern
1985) imitative skills are now studied intensively with the aim to understand their role in autism (see Williams et al.
2004). A second well documented area of impairment is impairment in use of joint attention behavior (Bono et al.
2004; Kasari et al.
1990; Leekam et al.
2000; Mundy et al.
1986; Sigman and Mundy
1989; Sigman and Ungerer
1984; Sigman et al.
1986). Children with autism show reduced frequency of initiating bids for joint attention with others by declaratively pointing to or showing objects (e.g., Baron-Cohen
1989a; Charman et al.
1997; Mundy and Willoughby
1996) and responding to others’ bids for joint attention (e.g., Leekam et al.
1997). Furthermore, several studies have shown that young children with autism, despite their ability to use gestures to request objects, tend not to use gestures to share interest in objects (Baron-Cohen
1989b; Charman et al.
1997; Mundy et al.
1986,
1993). This pattern of findings suggests that children with autism are not necessarily avoidant or unresponsive to social contact, but rather that there is reduced attention to others (Dawson et al.
2004), reduced interpersonal “resonance” with others (Rogers and Pennington
1991), or reduced intrinsic reinforcement from shared interactions with others (Dawson et al.
2004).
Only a few studies have focused on social behaviors like helping and cooperation in children with autism. Concerning helping, Sigman and Ruskin (
1999) included a measure of helping in a longitudinal study of people with autism. For example, when an experimenter could not perform an act because his/her hands were occupied, the 10- to 13-year-old participants with autism less frequently assisted the partner to reach his/her goal than children with Down syndrome. Regarding cooperation, Jahr et al. (
2000) conducted an intervention study involving cooperative play in six children with autism aged 4–12 years. They used materials that were familiar to the children from school and activities of the kind of one partner builds a fence and the other partner puts a toy animal inside the fence. They instructed the participants to either repeat cooperative play episodes they had observed two models acting out or to verbally describe what they observed first before they repeated themselves. Training was conducted until a certain criterion of correct imitation of the models in the imitation condition or correct verbal description and imitation in the verbal condition were achieved. In the following test Jahr et al. measured units of consecutive play between the child and the partner. They found that none of the children achieved the criterion during a baseline before the training and that they did so only after training with verbal description. After this kind of training, they maintained the increased performance in the test with novel settings and novel partners and during follow-up after 1 month. An open question remains whether the activities reflect full-fledged cooperation with two partners having shared goals and shared intentions. To address this question, in our cooperation study we included interruption periods to investigate children’s understanding of the partner’s role within a cooperative activity when interaction breaks down. Another study by Downs (
2003) surprisingly found that 5- to 9-year-old high functioning children with autism cooperated similarly to a group of typically developing children in a Prisoner’s Dilemma task. The author discusses the finding in terms of the suitability of the task as the children interacted with an imaginary friend. However, in addition he promisingly argues that the children received intensive behavioral treatment which might have improved their cooperative skills. To conclude, the reported studies addressed helping and cooperative activities in older children with autism. Our studies aimed to investigate these behaviors in younger children with autism, independent from language.
To summarize, the current studies aimed to investigate social behaviors in children with autism compared to children with other developmental delay. To assess helping (Study 1), we adapted a subset of tasks from Warneken and Tomasello (
2006), in which an adult is struggling to grasp out-of-reach objects. Based on the theoretical proposal by Tomasello et al. (
2005) and findings of intact intention reading in children with autism, we predicted that children with autism might show no deficits in helping behaviors that involve an understanding of other people’s individual goals and the motivation to assist. To assess cooperative behavior (Study 2), we adapted the tasks from Warneken et al. (
2006). Children interacted with an adult partner who stopped carrying out her role during predetermined interruption periods. In this manipulation we were particularly interested to see if children tried to re-engage the partner, which would indicate that they understood the partner’s role in the joint activity. Based on the theoretical account by Tomasello et al. and well-known deficits of imitation and joint attention, we predicted that shared cooperative activities would be a challenge for children with autism, as they require coordination of attention among self, partner, and task (joint attention abilities) and the formation of shared goals and intentions (plans of action) with the partner.
Because the tasks do not rely on receptive and expressive language, they appeared particularly appropriate for testing young children with autism, given the language difficulties they typically demonstrate. This allowed us to differentiate helpful and cooperative behavior from the verbal impairment generally identified in autism.