Our broad approach to social cognition is matched with a corresponding broad approach to physical cognition. Thus we study various aspects of physical cognition that can inform us about the cognitive processes that the great apes use to solve problems. We have focused our attention on three main areas: spatial cognition, planning, and causal knowledge.
Spatial cognition and memory
We have investigated spatial frames of reference from a phylogenetic, ontogenetic and cross-cultural perspective. We have found that nonhuman apes and 1-year-old children focus their attention on spatial information (e.g., the container located on the right side) whereas 3-year-old children pay more attention to the container features (e.g., the round and brown container). This has led us to hypothesize that at least in the great ape family, spatial coding is more ancient than featural coding. Further studies suggest that culture, and language in particular, plays an important role in the development of this in human ontogeny. We have continued to work on how apes encode and retrieve spatial information from memory. Previously we had established that orangutans can remember what is where. However, this has never been systematically quantified and it is unknown how much exposure is necessary to acquire such knowledge. We investigated the speed of acquisition and the long-term retention of food locations in chimpanzees by hiding rewards in their indoor area and measuring whether they revisited those locations once they had discovered the reward on a previous day. We found that chimpanzees were capable of remembering food locations after a three-month period