Bibliography (6):

1. Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis

2. Chimpanzees (Pan Troglodytes) Recognize Spatial and Object Correspondences Between a Scale Model and Its Referent

3. Ravens parallel great apes in physical and social cognitive skills

4. Wikipedia Bibliography:

   1. Cognitive psychology

   2. Center embedding

   3. Mixture model