Sequences of reward magnitude and runway performance

Three groups of rats underwent 24 days of training and 12 days of extinction (three trials per day) in a runway under conditions of increasing (I), decreasing (D), and random (R) sequences of reward magnitudes (0, 45, and 500 mg). The I Ss ran faster over the daily trials, the D Ss slowed down, and the R Ss ran at approximately equal speeds on each trial. The patterned running observed in training persisted in extinction, with the R Ss running fastest and the I Ss next. The results were discussed in terms of Capaldi’s sequential theory and Amsel’s frustration theory.     

Performance of Montessori and traditionally schooled nursery children on tasks of seriation, classification, and conservation

It was hypothesized that the Montessori curriculum accelerates the acquisition of a number of concrete operational skills. To test this, eighty 4-year-old children were given three Piagetian problems—seriation, classification, and conservation. Half of the subjects were from Montessori schools, and the other half were from more traditional nursery settings. Within each type of school, half of the children were first year and the other half were second year enrollees. Results showed that significantly more Montessori than traditional children seriated and classified objects like concrete thinkers but that there were no differences on the conservation problem. Year of enrollment did not influence performance on any of the tasks. It was concluded that the hypothesis was confirmed and that the failure to find acceleration of conservation performance was due to its advanced nature relative to the other problems and/or the tangential manner in which Montessori exercises deal with the critical concepts that underly it.     

Open-field behavior of wild and domestic Norway rats

The open-field behavior of wild and domestic Norway rats was compared in 15-min tests administered over 5 successive days. Wild rats exhibited more ambulation, jumping, grooming, and time inactive than domestic rats and spent more time along the arena wall. Within- and between-trial changes in behavior were generally greater for wild rats. Factor analyses revealed major loadings on factors identified as “locomotor behavior” and “grooming.” Support was obtained for the hypothesis that domestication has raised the threshold for avoidance-escape behavior in response to a novel environment.     

Relation between ITPA average deviation and Stanford-Binet intelligence scores

The relation between average deviation, as determined using the Illinois Test of Psycholinguistic Abilities, and Stanford-Binet intelligence scores was examined using a preschool sample. The results revealed a curvilinear (quadratic) relation between total average deviation and Stanford-Binet intelligence scores. The use of average deviation as an index of “learning disabilities” was discussed.