their life and gain knowledge about their specific culture based on things the adults around them do. They do this through mediation and scaffolding. Speculated core systems of cognition Empiricists study how these skills may be learned in such a short time. The debate is over whether these systems are learned by general-purpose learning devices or domain-specific cognition. Moreover, many modern cognitive developmental psychologists, recognizing that the term "innate" does not square with modern knowledge about epigenesis, neurobiological development, or learning, favor a non-nativist framework. Researchers who discuss "core systems" often speculate about differences in thinking and learning between proposed domains. Researchers who posit a set of so-called "core domains" suggest that children have an innate sensitivity to specific kinds of patterns of information. Infants appear to have two systems for dealing with numbers: the subitizing system deals with small numbers, then as the numerical values increase, human infants use a seemingly randomizing system to make decisions in their current predicament. Very young children appear to have some skill in navigation. This basic ability to infer the direction and distance of unseen locations develops in ways that are not entirely clear. However, there is some evidence that it involves the development of complex language skills between 3 and 5 years. Also, there is evidence that this skill depends importantly on visual experience, because congenitally blind individuals have been found to have impaired abilities to infer new paths between familiar locations. One of the original nativist versus empiricist debates was over depth perception. There is some evidence that children less than 72 hours old can perceive such complex things as biological motion. However, it is unclear how visual experience in the first few days contributes to this perception. There are far more elaborate aspects of visual perception that develop during infancy and beyond. Young children seem to be predisposed to think of biological entities (e.g., animals and plants) in an essentialist way. This means that they expect such entities (as opposed to, e.g., artifacts) to have many traits such as internal properties that are caused by some "essence" (such as, in our modern Western conceptual framework, the genome). A major, well-studied process and consequence of cognitive development is language acquisition. The traditional view was that this is the result of deterministic, human-specific genetic structures and processes. Other traditions, however, have emphasized the role of social experience in language learning. However, the