A HULLIAN CONSTANT AS AN INDEX OF INTELLIGENCE: TWO EMPIRICAL INVESTIGATIONS

Following Clark Hull, it is widely considered that the asymptote of the learning curve represents motivational factors, but that rate of approach to asymptote ('i') represents associational factors. The suggestion that i may be a measure of intelligence was tested empirically in two studies. An initial exploratory study yielded a positive correlation between i and IQ. A more rigorous replication did not. The results are discussed briefly.     

“Higher” and “lower”: Comparative and categorical interpretations by children

Three-, four-, and five-year-old children's categorical and comparative understanding of high and low were examined in two experiments. Categorical knowledge was assessed by presenting subjects with a single object at varying heights (from 0 to five feet above the ground), and asking if the object was high or low. Comparative understanding of the terms was assessed by showing children two objects at a time and asking which was higher or lower. We observed two patterns of performance in children's categorical treatments: younger children in particular defined disjoint categories for high and low such that they only labelled the extreme heights as high or low, and maintained that middle heights were neither high nor low. Older children defined either-or categories such that all heights were labelled either high or low. We also found that children who defined either-or categories made correct comparative judgments across the entire range of variation whereas children who defined disjoint categories could only judge which of two objects was higher if the objects were not low (at 0 and 1 feet) and which of the objects was lower if the objects were not high (at 4 and 5 feet). The results were interpreted as reflecting a lack of appreciation that the terms are interdefined as negations of each other, and were discussed in terms of the similar semantic-congruity effects found in adults.     

Memory impairment following ruptured aneurysm of the anterior communicating artery

This study reports the case of a 42-year-old man who suffered a ruptured aneurysm of the anterior communicating artery. His memory capabilities were assessed after a considerable recovery period during which many of his memory deficits ameliorated. His scan revealed a left frontal lesion and many of his deficits were characteristic of frontal impairment. He was impaired on temporal discrimination, and he showed marked source forgetting. He also performed badly on the Brown-Peterson task, and we suggest that this is another task that may be characteristic of frontal impairment. In contrast, the patient showed normal or near normal performance on some memory tasks but not on others. It is concluded that the patient's frontal signs are similar to those found in Korsakoff's Syndrome, but that his memory impairment is qualitatively different from that encountered in patients with the amnesic syndrome.     

Comparison of K-ABC performance between at-risk and normal preschool children

This study examined differences in K-ABC performance between at-risk (n = 44) and normal (n = 49) preschool children. For the group at-risk, all of the mean global scores on the K-ABC clustered around a standard score of approximately 90. The normal group's mean scores were 15 to 21 standard-score points higher and clustered near 110. The results of t tests for independent samples indicated that the normal group's scores on both the global scales and K-ABC subtests were significantly higher than the at-risk group's scores in nearly every instance. Correlations among scores were consistent with previous findings for preschoolers on the K-ABC. For the normal group, correlations obtained among the global scales were nearly identical to those reported for the standardization sample. For the at-risk group, however, the correlation of .75 between Sequential processing and Achievement was higher than that (.58) between Simultaneous processing and Achievement.