A confluence model is developed that explains the effects of birth order and family size on intelligence. (Editor)

Methods that have been employed in McGill University's (Montreal, Quebec) program of research into the nature of learning are described. The methods illustrate four phases of inquiry: conceptualization or model-building; data gathering techniques; data representation; and data analysis. For the university's learning task project, the development…

Current theories of intellectual development claim that such development proceeds through invariant sequences of increasingly more adequate cognitive structures. According to the two dominant theories on changes in intellectual functioning during adulthood, intellectual development is essentially accomplished by adolescence, although sharpening…