Operationalization and measurement

Operationalization and measurement
Biological models of information processing have been studied almost invariably in laboratory settings. A major aim of our research has been to study information processing in daily life situations. The situations were derived from an extensive taxonomy of situations developed by Van Heck (1989), in which over 200 situations have been defined meticulously in terms of cues and features. For the experimental study of information processing 25 situations were selected and cast in films (Hettema et al., 1989; Hettema, 1994). During the films seven psychophysiological reactions presumably relevant for the Pribram-McGuinness model were measured continuously. Reactions included heart interbeat intervals (HIV), pulse transit time (PTT), T-wave amplitude (TWA), galvanic skin response level (GSL), finger temperature (FTT), diastolic blood pressure (DBP), and
systolic blood pressure (SBP). The pattern of physiological reactions was taken to reflect information processing at each moment in time. This claim was tested in different studies
(Hettema et al., 2000). Our analyses included several thousands of reaction patterns. First, after proper standardization correcting for time trends as well as for base levels, on
the basis of covariations among the measures we derived three dimensions, interpreted as
arousal, activation and effort. Subsequently, the specific characteristics of each dimension were tested. As expected, the arousal dimension was particularly sensitive to novelty induced with films mismatching existing expectancies. The activation dimension was sensitive to evaluative aspects, i.e. good versus bad. Evaluations were induced with positive versus negative explanations of the films’ content prior to exposition. The effortdimension reflected involvement versus detachment on the side of our subjects, induced through instructions emphasizing involvement versus detachment. Finally, in a separate study we found evidence on the nature of each dimension to reflect controlled versus automatic processing. We concluded that our three dimensions represented arousal, activation and effort as proposed by Pribram and McGuinness (1975, 1992).
Individual differences
A major problem yet to be solved is individual differences in information-processing energetics. Since the Pribram-McGuinness model was neither intended nor ever used to study individual differences this was a major question to be answered. We were especially interested in the consistency of individual reactions across different situations. To that effect for each dimension we analysed the reactions of our Ss during seven different films and tested for consistency across situations. Intraclass correlations were 0.80 for arousal, 0.84 for effort, and 0.84 for activation indicating high levels of consistency across situations (Hettema et al., 2000). These results suggest that in each dimension the ordering of subjects remains about the same no matter the situation in which testing is done. It should be stressed here that situations have sizable overall effects upon reactivity as well so that reactions actually observed within the same subject tend to show variation across situations as well.

GALTON AND INDIVIDUAL DIFFERENCES

GALTON AND INDIVIDUAL DIFFERENCES
Francis Galton can be credited with the first systematic, scientific attempt to both understand and measure human intelligence . Galton’s essential idea was that there are stable,biological differences in intelligence between people.‘I have no patience with the hypothesis . . . that babies are born pretty much alike, and that the sole agencies in creating differences between boy and boy, and man and man, are steady application and moraleffort,’ he wrote. ‘The experiences of the nursery, the school, and of professional careers, are a chain of proofs to the contrary’ (1892, p. 12). Galton considered intelligence to be a low-level property of our nervous system that we inherit from our parents.He believed that individual differences in intelligence reflect differences in the efficiency of operation of simple neural processes.
Galton pursued his theory in several ways – first, by constructing extensive family trees of ‘persons of reputation’ in one domain or another to investigate patterns in eminence and achievement within families. His book Hereditary Genius, first published in 1869, presents family trees of ‘Commanders, men of Literature and of Science, Poets, Painters and Musicians of whom history speaks’ to support his hypothesis.