10 - Prepared to learn about human bodies’ goals and intentions

Summary

Human beings are one of the first and one of the most frequent ‘objects’ in infants’ environment. Infants’ interactions with their caregivers are extremely diverse and socially rich. Caregivers provide care, affection and knowledge. It therefore seems trivial to assume that one of the first things human infants will learn is how to identify their conspecifics. The first section of this chapter reviews a series of studies that contradict the above intuition. Experimental research presented in this section has shown that infants, prodigiously good at learning about faces, are slow at learning about the human body appearance. A few explanations have been put forward to integrate these conflicting findings. Faces and bodies are similar in many respects (e.g. they have component parts whose relative position is species-specific; minor variations in the distance between these components occur between individuals) but also different in others (e.g. body parts movement leads to ampler structural changes than face component movements and these movements are often object-oriented). Thus, because movement changes the outline of bodies it may be more difficult to build a prototype of the human body than of the human face. Alternatively it could be that body movement, particularly the goals of human action, grab infants’ attention, at the expense of learning about body structure. It has been proposed that infants’ learning about the structure of the human face is secondary to their learning about facial communicative cues like eye-contact and eye-gaze (Gliga and Csibra, 2007). In the second section we will review evidence in support of a similar developmental story for acquiring knowledge about body structure. We will show that, before acquiring precise knowledge on humans’ appearance, infants are proficient at understanding and anticipating human (body) action. This attentional bias is driven by their need to learn from others, which requires understanding other people’s goals and intentions. The final section will attempt to integrate these two lines of research. We will propose that the principles infants use to understand the goals of human actions can also be used to learn about which bodily actions are possible and which are not, and eventually about human body structure. We will bring arguments to support this view from both developmental and adult cognitive neuropsychology.