Institute for Mathematical Behavioral Sciences

A problem in the behavioral science is the lack of good way to compare “how smart” different animals humans are and how difficult the tasks they do are. Here, we set forth a general and powerful means. The mathematical Model of Hierarchical Complexity (MHC) posits that tasks can be absolutely ordered as to their hierarchical complexity. The Model also measures the stages of animal performance on this absolute scale. It does so by taking the actions that animals and humans engage in, and ordering them. Stage of performance has the same number and name as the corresponding order of hierarchical complexity of the task it correctly completes. An animal species is characterized by the highest stage of performance observed with any amount of training on it best task series. Animals perform up to the concrete stage, about what 8 to 10-year-old children do. Current theories are often based on human performances and may not easily apply to other species. We propose that such a theory include three-indexes: an index of the stage of development based on the order of hierarchical complexity of the tasks the species can perform; an index of horizontal complexity; and a measure of g. Here we propose a way to conceive of g in animals. Geary has argued that domain-general mechanisms are essential for evolutionary psychologists. We use existing research to enumerate domains, such as problem solving behavior in pursuit of food, or behaviors in pursuit of mates and/or reproduction. We then illustrate how to construct two forms of g, one across domains and one within domains.