Former Department of Developmental and Comparative Psychology
Max Planck Institute for Evolutionary Anthropology
Deutscher Platz 6
This group investigated basic processes of collaboration, communication, joint attention, imitation, normativity, and social cognition in human infants and young children. The main focus of the group was on children’s participation in various types of interactions involving shared intentionality. Related to this a continuing focus was on infants’ understanding of others’ intentional states – their ‘theory of mind’.
After having established that 1-year-old infants (unlike apes) engage in collaborative activities structured by joint goals, we investigated children’s understanding of these activities in a more fine-grained way. For example, we studied children’s reactions to different types of interruptions in the collaborative activity, and we measured how children share rewards with their partner and resolve conflicts and coordination problems in collaborative interactions. In addition, we looked at young children’s source-monitoring errors in collaborative vs. non-collaborative activities, and children’s understanding of the commitments and obligations engendered by collaborative activities.
Similarly, after showing that 1-year-olds altruistically help others, we further investigated the conditions under which infants help. We investigated the effects of the rewards infants receive for helping and the presence or absence of maternal encouragement. We have also investigated whom young children are likely to help, showing that early prosocial behavior is mediated by the needy other’s circumstances and moral behaviors.
Communication is a collaborative activity and we are finding some quite sophisticated abilities already in preverbal, 1-year-old infants. For example, infants (unlike apes) use common ground to interpret others’ pointing gestures (including gestures to third parties), and also produce pointing gestures differently depending on the experience they have shared with others. Slightly older children interpret others’ requests cooperatively, and cooperatively repair their own requests differently depending on the reason their communication failed. Further work on gestural communication includes a number of studies on 12-month-old infants’ pointing. We have shown that infants point for a variety of motives, including the prosocial motives of sharing attention and interest with others (so-called ‘declarative’ pointing) and helping others by informing. In particular, we have shown that infants point differently for knowledgeable and ignorant adults and adults who are currently attending versus not attending. Infants (unlike chimpanzees) can even point to communicate about absent referents. We also studied the development of pointing (including relations between comprehension and production of pointing) and young children’s (and apes’) ability to comprehend and produce iconic gestures.
In a series of studies, we have demonstrated that young children understand the intentional and normative structure of joint pretend games, and even can switch the assignment of a pretend status to an object as a function of specific persons and contexts. Young children also learn games normatively and protest when other agents violate the rules of the games. We also investigated young children’s normative understanding of possession and ownership. And we looked at children's internalization of social norms as evidenced by their comprehension of the guilt reactions of others.
Young children are thought to copy others both to learn from them and to affiliate with them socially, and we are investigating both types of imitation. For example, we have shown that young children selectively learn from adults versus peers and from reliable versus unreliable adults, and that they use an understanding of others’ goals and intentions when deciding what to copy from a demonstration. With regard to the social function of imitation, we have found relations between mimicry and helping and between affiliation to the group and imitation. We also investigated affiliation in young children using other methods.
Using various methods, we have shown that infants as young as 9-12 months of age understand not just others’ goals but also their intentions, the action plans they choose to achieve their goals. Similarly, 1-year-olds understand not just others’ perception but also their attention, that is, they know which particular object or aspect of an object others are focusing on within their visual field. We have found that 1-year-olds even understand others’ knowledge/ignorance, in the sense of what objects or events others have experienced in the past. However, even much older children have difficulty taking others’ visual perspectives. We have investigated under what conditions infants know what others know and can see from a perspective different from their own. We have found that sharing experiences with others in joint attentional engagement facilitates young children’s understanding of what others know, but hinders children’s understanding of what others can see. We have also shown that 3-year-olds know that two people can have mutually incompatible desires, and that this understanding is related to executive function. And using various new nonverbal methods, we studied 1-year-old infants’ understanding of others’ false beliefs.
Our general findings are that great apes and human infants are fairly similar in their understanding of others’ intentional states, but human infants go beyond apes in their skills and motivations for sharing intentions in such things as collaborative activities and cooperative communication.