Which is the real intelligence? A reply to Robinson (1999)

Robinson's ([Robinson, D.L. (1999). The ‘IQ’ factor: implications for intelligence theory and measurement. Personality and Individual Differences, 27, 715–735]) arguments that crystallized intelligence represents the “one valid intelligence factor” are disputed. It is argued that Robinson seriously underestimated the relevance of fluid abilities to “intelligence”, by using an inappropriate criterion for assessing the intelligence-saturation of cognitive ability variables. The relevance of fluid and crystallized abilities to popular, psychometric, and biological conceptions of intelligence is discussed, and the issue of age-related changes in fluid and crystallized intelligence is also addressed.     

Impact of encoding depth on awareness of perceptual effects in recognition memory

Pictorial stimuli are more likely to be recognized if they are the same size, rather than a different size, at study and at test. This size congruency effect was replicated in two experiments in which the encoding variables were respectively undivided versus divided attention and level of processing. In terms of performance, these variables influenced recognition and did not influence size congruency effects. But in terms of awareness, measured by remember and know responses, these variables did influence size congruency effects. With undivided attention and with a deep level of processing, size congruency effects occurred only in remembering. With divided attention and with a shallow level of processing, size congruency effects occurred only in knowing. The results show that effects that occur in remembering may also occur independently in knowing. They support theories in which remembering and knowing reflect different memory processes or systems. They do not support the theory that remembering and knowing reflect differences in trace strength.     

Relation between aging and research productivity of academic psychologists

Using a cross-sequential design involving four birth cohorts and five measurement periods, a curvilinear relation between aging and research productivity was found for more than 1,000 academic psychologists. Productivity typically began at a low rate in the 20s, increased to a peak around age 40, then decreased in the later years. Substantial individual differences were also observed. Those who began as high publishers remained more productive than the low or medium groups at each age level examined, and even at ages 55-64 they were more productive than the medium or low publishers were at their highest rate. Altogether, across cohorts and publishing levels, age accounted for 6.5% of the variance in publication rate from ages 25-34 to 55-64.     

Speed of information processing and general intelligence

This study investigates the relationship between a number of measures of speed of cognitive information-processing and intelligence test scores. One hundred university students were given five tests of speed-of-processing, measuring their speed of encoding, short-term memory scanning, long-term memory retrieval, efficiency of short-term memory storage and processing, and simple and choice reaction time or decision-making speed. They were also given the Wechsler Adult Intelligence Scale and the Raven Advanced Progression Matrices. A number of multiple regression analyses show that the cognitive processing measures are significantly related to IQ scores. Other analyses indicate that this relationship cannot be attributed to the common content shared by the reaction time and the intelligence tests, nor to the fact that parts of the WAIS are timed. It is concluded that the reaction time tests measure basic cognitive operations which are involved in many forms of intellectual behavior, and that individual differences in intelligence can be attributed, to a moderate extent, to variance in the speed or efficiency with which individuals can execute these operations.     

Tutor Attributions and Attitude As a Function of Tutee Performance1

In a single-session tutoring situation, a sixth-grade tutor taught a concept-formation task to a third-grade tutee. Over the series of trials, performance of the tutee was controlled to create differential patterns of success and failure on the task: success-success, failure-failure, success-failure, and failure-success. Results showed that sequence of performance exerted a strong impact on the tutor's attributions of ability and affective responses concerning the tutee. The tutee's initial performance had greater impact on the tutor's reactions than later performance, indicating a strong primacy effect. Differential performance by the tutee did not affect the tutor's evaluation of his own teaching ability.     

Binocular interaction of orientation and spatial frequency channels: Evoked potentials and observer sensitivity

The interaction between size and orientation feature processing in the human visual system was investigated. Both observer sensitivity (d’ss) and the visual evoked potential (VEP) to test gratings flashed to one eye were investigated as a function of the nature of a continuously presented suppressing grating viewed either by that same eye or the opposite eye. The test and suppressing gratings were varied both in bar width (9′ss vs. 36′ss) and orientation (vertical vs. horizontal). The continuous grating intra- and interocularly suppressed the monocular VEPs to the flashed grating, the specificity of the suppression depending on the latency at which VEP amplitude was measured. VEP amplitude measured at early latencies (100–125 msec) was suppressed primarily when the flashed and continuous gratings were the same orientation, regardless of size. Starting at about 200 msec, and thereafter, VEP amplitudes were suppressed when the continuous bars were either the same orientationor size as the flashed bars. Late latencies, starting at 220 msec, and thereafter, were suppressed primarily when the bars in the two gratings were the same orientation and size. The reduction in observer sensitivity (d′ss) paralleled the changes found in the late VEP measures. These effects were evident under both the intraocular and interocular suppressing conditions. This pattern of VEP suppression, measured across eight points in the VEP waveform, was interpreted as indicating the existence of a sequence of channels that are specific first to a particular grating orientation, then to either a particular grating spatial frequency or orientation, and finally to the conjunction of a particular orientation and spatial frequency. Both sequential and parallel feature processing appears to take place in the human visual cortex, with grating orientation being encoded earlier than grating size.