Correspondence analysis of incomplete contingency tables

Correspondence analysis can be described as a technique which decomposes the departure from independence in a two-way contingency table. In this paper a form of correspondence analysis is proposed which decomposes the departure from the quasi-independence model. This form seems to be a good alternative to ordinary correspondence analysis in cases where the use of the latter is either impossible or not recommended, for example, in case of missing data or structural zeros. It is shown that Nora's reconstitution of order zero, a procedure well-known in the French literature, is formally identical to our correspondence analysis of incomplete tables. Therefore, reconstitution of order zero can also be interpreted as providing a decomposition of the residuals from the quasi-independence model. Furthermore, correspondence analysis of incomplete tables can be performed using existing programs for ordinary correspondence analysis.     

Attribution bias: On the inconclusiveness of the cognition-motivation debate

Social psychologists have given considerable theoretical and research attention to whether motivational variables bias the attributions people make for behavior. Some theorists maintain that motivational constructs must be invoked to explain certain attributional phenomena; other theorists maintain that information-processing variables can adequately explain these phenomena. The present article critically examines existing cognitive and motivational approaches to attribution and analyzes the assumptions underlying the cognition-motivation debate. We argue that cognitive and motivational theories are currently empirically indistinguishable. In particular, its is possible to construct information-processing explanations for virtually all evidence for motivated bias. We conclude by examining the implications of this indeterminacy of cognitive and motivational explanations. Future research in the area can most profitably be addressed to improving the specificity of cognitive and motivational theories rather than to resolving the between-theory confrontation.     

Motor perseverative behavior in adult stutterers and nonstutterers

The performances of 22 adult stutterers and 22 adult nonstutterers on motor tasks requiring the graphic reproduction of a sequence of alternating figures following the production of a series of nonalternating figures were studied. The finding that there were no differences in the performance of the two groups on the alternating motor tasks was interpreted as challenging the validity of previous observations that motor perseverative behavior exists in stutterers and is indicative of a central neurological deficit in that population.     

A parent-offspring adoption study of cognitive abilities in early childhood

Do cognitive abilities in early childhood relate genetically and/or environmentally to isomorphic abilities in adulthood? Are specific cognitive abilities diffentiated in early childhood in terms of their prediction of adult cognitive abilities? The present study, the first behavioral genetic analysis of specific cognitive abilities in early childhood, explored these questions using parent-offspring data for 186 adopted children and 151 nonadopted children tested in the longitudinal Colorado Adoption Project at 3 years of age and 162 adopted children and 138 nonadopted children tested at 4 years. The children's Stanford-Binet IQ and scores for four specific cognitive abilities (verbal, spatial, perceptual speed, and memory) were correlated with corresponding measures for their parents—the biological and adoptive parents of the adopted children and the natural parents of the nonadopted children. Significant correlations were found between biological mothers' IQ and the IQ of their adopted away offspring at 3 and 4 years of age, suggesting genetic influence for IQ. However, specific cognitive abilities yielded no significant correlations between biological mothers and their adopted-away offspring. These results suggest that substantial genetic continuity exists for IQ from early childhood to adulthood, but not for specific cognitive abilities.     

Reaction times and speed-of-processing: Their relationship to timed and untimed measures of intelligence

Eighty-one university students were given a battery of reaction time tests, measuring the speed with which they performed various elementary cognitive processes, and a group test of intelligence which yielded timed and untimed scores. Multiple regression analyses indicated that speed of information-processing was an equally good predictor of timed and untimed intelligence test performance, and that various combinations of speed-of-processing variables accounted for as much as 48% of the variance in intelligence test scores. Different speed-of-processing variables varied relatively systematically in the extent to which they correlated with the individual subtests and scales of the intelligence test.     

Effects of noise on sensitivity of introverts and extraverts to signals in a vigilance task

Forty Ss, previously classified as introverts or extraverts on the basis of scores on the Eysenck Personality Inventory, performed a visual vigilance task while being stimulated with noise at an intensity level of either 65 or 85 dB. Introverts given noise of 65 dB intensity showed an improvement in detection rate across trials, whereas introverts given noise of 85 dB intensity showed a decline in detection rate. Extraverts responded to noise of 65 dB intensity with a slight decrease in detection rate, but showed an improvement in detection over trials when noise of 85 dB intensity was given. When noise of the lower intensity was given, introverts showed greater sensitivity to signals than extraverts. When noise of the higher intensity was given, introverts and extraverts were equal in sensitivity. The results are discussed in terms of a hypothesized relationship between stimulation and arousal, with E-I as a moderator variable.