ABSTRACT
Looking along a long object is a preliminary action for the formation of a line-ofsight. A hollow, tubular object is ideal in this respect because one may look straight through it. Understanding lines-of-sight is a prerequisite for the building up of knowledge about projective geometry. Human children’s development of spatial understanding follows roughly the same sequence as that of the chimpanzees. First of all a topological geometry dominates, concerned with inside and outside, closure, boundary, hollowness and
things which touch. This is coupled with dynamic knowledge derived from movement made through space and time, and the shapes one can make by simply moving. Later, a Euclidean geometrical understanding emerges in which the shapes of objects are noticed. Later on still, the relationship in space between objects is noted in relation to the viewpoint of the observer. This last type of geometrical understanding is projective, in that it captures relationships in three-dimensional space as if projected to the eye of a viewer. Children’s drawing shows this sequence of development clearly (Matthews, 1984, 1999, 2003, 2010; Willats 1997, 2005). I have not as yet discerned projective relationships in chimpanzee drawing and (though I could be wrong), I suspect it is not present. Of course, it would be fascinating if someone could contradict this. Even so, in the present study, the fi rst part of a developmental sequence we see in human childhood, from topological, haptic and dynamic thinking to the fi rst primitives of Euclidean geometry can be seen in the actions the chimpanzees perform upon objects. In human childhood, an awareness of projective relationships is the last of a series of geometrical understandings to appear, when children begin to grasp the signifi cance of view-specifi c information. These emergent concepts – fi rst, going-through, then looking-through – are extremely powerful in terms of the cognitive events to which they lead. Glimmerings of this type of thinking are present in the 4-year-olds’ use of a video-camera (page 233), which of course depends upon an understanding of line-of-sight and point-of-view (Matthews, 2006a). (See also Figures 24.1-24.4, later in this chapter.) Another pertinent example is offered by Betsy Herrelko’s fascinating (2010) experiment in which she gives the chimpanzees a video-camera in a rugged box. The videographic results she obtains seem to be more the product of the chimpanzees’ random handling of the box than of any awareness that they are videorecording or even just viewing a videographic representation. When I give video-cameras to 2-to 5-year-old children (Matthews, 2006a), over the course of weeks and months they learn naturally, with no overt instruction necessary, to use the video-cameras because they base its use on their emergent concepts of goingthrough and looking-through. They come to realise that they can look-through (‘virtually’) this electronic device in a fashion which emulates the way they can look through tubular volumes. In contrast, in Dr Herrelko’s experiment, the chimpanzees almost certainly understand the ‘chimpcam’ fi rst and foremost as a box and are probably preoccupied with trying to break it open to see what is inside (despite Herrelko’s care to insert the camera securely so that there is no tell-tale rattle). Chimpanzees are tool-users and if you give someone a tool, hoping he or she will use it then the function of that tool must be apparent or at least discoverable. I predict that, if the chimpanzees are given a more tube-like device, they will, like children, quickly realise that it can be (virtually) looked-through and then we will see our fi rst genuine videographic representations made by a non-human person. As we have seen, in their everyday actions, chimpanzees show an excellent understanding of line-of-sight and point-of-view, being able to hide from each other, both for real and in play and also sometimes (when they are in the mood)
from me, in what looks like a ‘peepbo’ type of play. As well as presenting objects clearly within their own fi eld of view (using usually their front-hands) they also know something about another’s point-of-view and, if they want to be noticed, will intentionally insert themselves, or an attractive object, into another’s range of vision. One example, is when a young chimp will purposely run across another’s fi eld-of-vision in order to provoke a chase. After 2 years 3 months of observations I am intrigued to fi nd that some chimpanzees have started to insert themselves purposely into the range of vision of my video-camera.
