Intelligence Tests and Theory: Multiple Intelligences and Psychobiology

Gardner’s Theory of Multiple Intelligences

• Foundational Concept (1983): Howard Gardner proposed a theory of intelligence motivated primarily by educational and practical utility. He argued that Western formal education systems are significantly biased towards two specific types of intelligence: "logical-mathematical" and "linguistic."

• Core Argument: Gardner posits that intelligence is not a single, general ability ($g$), but rather a collection of many different, interactional, but separate kinds of intelligence.

• Criteria for Identification: Gardner used specific criteria to identify these distinct intelligences, heavily applying understandings of neurology.

• Modular View of the Brain: This theory relies on the concept of relative independence among different functions in the brain. Because of this modularity, intelligences are considered relatively independent of one another; for example, a student might excel in only one specific intelligence while struggling in others.

• Interaction of Intelligences: While separate, these intelligences can be used together to perform complex skills. An example provided is dancing, which requires the interaction of musical intelligence and bodily-kinaesthetic intelligence.

The Nine Multiple Intelligences

Gardner initially identified 7 intelligences, which later expanded to 9:

• Linguistic: Related to language and verbal abilities.

• Logical-Mathematical: Related to numerical and logical reasoning.

• Spatial: Related to the perception and navigation of space.

• Musical: Related to rhythm, pitch, and musical patterns.

• Bodily Kinaesthetic: Related to the use of the physical body to solve problems or create products.

• Interpersonal: Related to understanding and interacting effectively with other people.

• Intrapersonal: Related to the understanding of oneself, one's own feelings, and motivations.

• Naturalist: Related to interacting with nature and understanding biological systems.

• Existentialist: Linked to spiritual thinking and the capacity to deal with deep questions about human existence.

Evaluation and Criticisms of Gardner

• Educational Influence: The theory has had a strong, largely ideological influence within the field of education. It shifts focus away from abstract theoretical definitions of intelligence toward identifying what is necessary to unlock the individual potential of any given student.

• Gardner’s Philosophical Stance: He views the theory as a victory for undermining the previously "narrow" conception of intelligence.

• Data Biases: Critics argue the theory is based on observations of existing data rather than new experimental evidence. This leads to concerns that Gardner may have been biased when selecting data to support his proposals.

• Statistical Deficiencies: The theory has not been statistically analyzed because its content is not structured in a way that permits standard psychometric testing. Gardner himself argues against conventionalIQ tests.

• Lack of Testing: The theory has not been extensively tested in a scientific or empirical capacity, though Gardner suggests it could, in principle, be measured.

Intelligence and the Cognitive Approach: Processing Speed

• Reductionist Research: Unlike Gardner, a body of cognitive psychology research attempts to find ways to reduce general intelligence ($g$) to its most fundamental components.

• The g Factor and Neural Efficiency: Arthur Jensen (1998) argued in "The g factor: The science of mental ability" that at the level of causality, $g$ is a source of variance in performance associated with individual differences in the speed or efficiency of neural processes.

• Elementary Cognitive Tasks (ECTs): Jensen utilized ECTs to measure intelligence because they are relatively unaffected by past experience, prior knowledge, or formal learning.

Reaction Time and the Jensen Box

• Hick’s Reaction Time Procedure: Jensen designed the "Jensen Box" to measure choice reaction time (RT) through a specific procedure:

  • The participant places a finger on the "home button."

  • One of several (out of $1$, $2$, $4$, or $8$) light/buttons is illuminated.

  • The timer starts when the light appears.

  • The participant lifts their finger from the home button, at which point the first timer stops. This measures "Decision Time" or Jensen’s RT.

  • A second timer starts immediately upon the finger being lifted.

  • The participant presses the target button, and the second timer stops. This measures "Movement Time."

• Correlational Evidence for RT and IQ:

  • Jensen (1987): A review of $26$ studies with over $2000$ participants found that overall mean RT and IQ correlated at $-0.20$.

  • Detterman (1987): Found a correlation of $r = -0.32$ in a study of $141$ seventeen-year-olds.

  • Scottish Representative Sample: A study of $900$ fifty-five-year-old Scots found a correlation of $r = -0.49$.

• Critical Conclusion: Even the highest correlations do not suggest that reaction time and $g$ are equivalent.

Inspection Time (IT) as a Measure of IQ

• Definition: Inspection Time measures the time required for a person to sample visual or auditory information from the external world.

• Mechanism: It is NOT a measure of reaction speed and does not involve a speeded response. Instead, it measures the number of errors or the duration of inspection at which errors begin to occur (e.g., determining which side of a stimulus is longer).

• Trial Structure: Stimuli are typically preceded by a fixation cross/cue, shown for a brief duration ($1$-$500$ msec), and followed by a mask.

• Correlational Evidence for IT and IQ:

  • Early studies reported extremely high correlations ranging from $-0.70$ to $-0.92$.

  • Grudnik & Kranzler (2001): A meta-analysis of $92$ studies (over $4000$ participants) found a more modest correlation of $r = -0.30$.

  • Conclusion: The overall evidence suggests that IT is not measuring something equivalent to $g$.

The Psychobiology of Intelligence

• Biological Factors Studied: Physiology/Anatomy (brain size, activation) and Psychophysiology (electrical activity recorded via Event-Related Potentials or ERPs).

• Caveat: Dr. Hall warns that "brain science is not necessarily better science."

• Brain Size and IQ: Efforts to relate head size to intelligence predate modern IQ tests. While human brain size increased threefold over the past three million years, it has actually decreased over the last $100,000$ years (Aiello & Dean, 1990).

• Correlations with Brain Size:

  • Willerman et al. (1991): $r = .35$ ($40$ US university students).

  • Raz et al. (1993): $r = .43$ ($29$ adults).

  • McDaniel (2005): Meta-analysis of $37$ samples ($1530$ participants) found $r = .33$.

• Interpretation: IQ seems to be associated with volumes in all association areas of the cortex, suggesting that IQ performance is a single measure distributed across all brain areas rather than being localized. It is also noted that IQ is associated with birth weight and height.

Brain Speed and Neural Efficiency

• ERP Latency: An Electroencephalograph (EEG) records electrical brain activity related to stimulus processing. The P300 peak (P3) is elicited by an "odd-ball" task. The latency (onset time) of the P300 is negatively related to IQ (higher IQ equals faster onset).

• Neural Efficiency Hypothesis: Surprisingly, many activation studies find NEGATIVE correlations between IQ and brain activity during mental tasks.

  • Common Explanation: Higher IQ individuals use brain resources more "efficiently."

  • Alternative Explanation: Higher IQ individuals simply find the task easier, leading to reduced activation (Mackintosh, 2011).

• Parieto-Frontal Integration Theory (P-FIT): Proposed by Jung & Haier (2007) based on a review of $37$ brain activation studies. It argues that individual differences in intelligence stem from the operational differences in a network involving the parieto-frontal brain regions.

Cognitive Intelligence Tests Based on Luria

• Aleksandr Romanich Luria (1966): Conducted clinical studies shift with "frontal" patients who displayed an inability to execute plans. Luria distinguished between "simultaneous" and "successive"/sequential processing.

• Das and Naglieri’s Cognitive Assessment System (CAS): Based on the PASS system:

  • Planning: Goal-setting and monitoring (localized in the frontal lobe).

  • Attention-Arousal: Involves the brain stem, thalamus, and regions of the frontal lobe.

  • Simultaneous Processing: Integrating information as a whole (occipital and parietal lobes).

  • Successive Processing: Sequencing stimuli in order (frontal-temporal region).

  • The CAS contains $12$ subtests ($3$ for each PASS competency) and is used for ages $5$-$17$.

• Kaufman’s Ability Tests (K-ABC, KAIT, K-BIT): Influenced by Luria’s neuropsychological model and the Cattell-Horn-Carroll (CHC) model. These tests measure:

  • Achievement: Specifically reading and arithmetic.

  • Simultaneous Processing: Integrating disparate information.

  • Sequential Processing: Arranging stimuli in a specific order.

Questions & Discussion

• MCQ 1: What is the relationship between brain size and intelligence?

  • Answer: Positive (correlations identified around $r = .33$ to $.43$).

• MCQ 2: Luria distinguished between what two kinds of processing?

  • Answer: Simultaneous and sequential processing.

• MCQ 3: What field has Gardner’s multiple intelligence theory influenced?

  • Answer: Education.

• Question for Thought: If an association is found between a biological feature and IQ, what are the three possible explanations for this association? (Consider direct causation, common underlying factors, or environmental mediation).

• Biological Predications (Vevox Poll Tasks):

  • Brain Size: Higher IQ corresponds to larger brain volume.

  • Brain Speed: Higher IQ corresponds to faster functioning (lower latency).

  • Brain Activity: Higher IQ often corresponds to less activity (efficiency) during mental tasks.