Richard A. Griggs

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Problem. An abstract problem with “true/false”, rather than “violated”, instructions was employed. The specific problem and instructions were adapted from Platt and Griggs (1993b, p.596) and were as follows: Each of the boxes below represents a card lying on a table. Each one of the cards has a letter on one side and a number on the other side. Here is a(More)
The consequences of chronic methylphenidate (MPH) administration in adolescents for the treatment of attention-deficit/hyperactivity disorder (ADHD) remain to be fully understood. Studies in rats indicate that the pharmacokinetics of psychostimulant administration can powerfully influence the behavioral and neural consequences of chronic treatment. The(More)
In four experiments with 760 subjects, the present study examined Cosmides' Darwinian algorithm theory of reasoning: specifically, its explanation of facilitation on the Wason selection task. The first experiment replicated Cosmides' finding of facilitation for social contract versions of the selection task, using both her multiple-problem format and a(More)
The effects of type of recognition test procedure were studied in a Bransford and Franks (1971) integration paradigm. Subjects received a two-alternative forced-choice recognition test or a modified "forced-choice" test in which all the sentences for each idea set were presented at once and the "old" sentences had to be identified. Contrary to the usual(More)
Using the analogical transfer paradigm, the present study investigated the competing explanations of Girotto and Legrenzi (Psychological Research 51: 129-135, 1993) and Griggs, Platt, Newstead, and Jackson (Thinking and Reasoning 4: 1-14, 1998) for facilitation on the SARS version of the THOG problem, a hypothetico-deductive reasoning task. Girotto and(More)
Subjects learned and answered questions about four-term linear orderings described in paragraphs of text. Spacing along the dimension employed was varied by using verbal quantifiers ("just barely," "moderately," and "very much"). After learning the quantitative information, performance on ordinal information varied as a function of the quantitative(More)