Investigates the asserted differences in reasoning between adults and second, fourth, and sixth graders in a manipulation of variables task using class inclusion and story problems with common everyday situations. Results are discussed in terms of sensible reasoning and problem-solving skills. (CM)

According to Humean framework, relations are judged to be causal to extent that they are characterized by regularity, continuity, and covariation among college students and college-bound 11- and 14-year-olds. Presents subjects with information about one of the following indices: potential causal factor covaried with effect and potential causal…

Children in grades 1, 3, and 5 and college students were given a variety of judgment tasks contrasting the comparison of quantity with the comparison of proportions to determine whether the understanding of proportions develops before formal operations. Results indicated that the comprehension of abstract relations requires formal operations.…

Tested hypothesis that understanding validity of inference is a relatively late development by asking fourth and seventh graders and college students to sort sets of deductive arguments. None of fourth graders, 45 percent of seventh graders, and 85 percent of college students used validity as basis for distinguishing arguments. Experiments…

Examined the conceptions of freedom of speech and religion held by 48 adolescents and young adults, using a structured interview containing assessments of civil liberties in general, in straightforward applications, and in conflict with other social and moral concerns. Findings indicate that sophisticated conceptions of civil liberties emerge by…