Group ownership is ubiquitous-property is owned by countries, corporations, families, and clubs. However, people cannot understand group ownership by simply relying on their conceptions of ownership by individuals, as group ownership is subject to complexities that do not arise when property is individually owned. We report 6 experiments…

A general theory of how children learn conservation concepts is presented. The acquisition process is described at an abstract level in terms of a rule-sampling system, implying a three-state Markov model with identifiable parameters. Three experiments testing the model's quantitative predictions about conservation learning experiments are…