Measurement of Intelligence

Overview

Measurement of intelligence is a foundational topic in Child Development and Pedagogy that helps teachers understand how cognitive abilities can be assessed and what these assessments mean for classroom practice. For TS TET, you must understand the concept of Intelligence Quotient (IQ), know the major intelligence tests by name and developer, and critically evaluate how intelligence testing influences educational decisions.

This topic connects directly to inclusive education and individual differences. Questions typically ask about IQ formulas, classification of intelligence levels, names of specific tests, and the limitations of intelligence testing. Understanding this topic helps future teachers avoid labelling children unfairly while still using assessment data to support diverse learners.

Key Concepts

• **Intelligence Quotient (IQ)** is a numerical score representing an individual's cognitive ability relative to their age group. It was originally calculated as (Mental Age ÷ Chronological Age) × 100.

• **Mental Age (MA)** refers to the level of intellectual functioning compared to the average performance of children at various ages. A child with MA of 10 performs like an average 10-year-old regardless of actual age.

• **Chronological Age (CA)** is the actual age of the child in years and months from birth.

• **Deviation IQ** is the modern method where IQ is calculated based on how far an individual's score deviates from the mean of their age group. Mean is set at 100, standard deviation at 15.

• **Normal distribution** of IQ means most people (about 68%) score between 85-115, with very few scoring extremely high or low.

• **Standardisation** ensures that intelligence tests are administered uniformly and scores can be compared across populations.

• **Reliability** means the test produces consistent results over time; **validity** means it actually measures intelligence.

• **Culture-fair tests** attempt to minimise bias from language, education, and cultural background.

Formulas / Key Facts

**Classic IQ Formula (Stern's Formula):** IQ = (Mental Age ÷ Chronological Age) × 100

**Example:** A child aged 10 years with mental age of 12 years: IQ = (12 ÷ 10) × 100 = 120

**IQ Classification (Terman's Classification):** | IQ Range | Classification | |----------|----------------| | Above 140 | Genius/Near genius | | 120-140 | Very superior | | 110-120 | Superior | | 90-110 | Normal/Average | | 80-90 | Dull | | 70-80 | Borderline | | Below 70 | Intellectually disabled |

**Major Intelligence Tests:**

• **Binet-Simon Scale (1905)** — First practical intelligence test, developed in France
• **Stanford-Binet Test (1916)** — Terman's American revision, introduced IQ term
• **Wechsler Scales** — WAIS (adults), WISC (children), WPPSI (preschool)
• **Raven's Progressive Matrices** — Non-verbal, culture-fair test
• **Cattell's Culture Fair Test** — Minimises cultural and educational bias
• **Army Alpha and Beta Tests** — Group tests developed during World War I

**Key Facts:**

• Average IQ is always 100 by definition
• About 2.5% of population scores above 130 (gifted)
• About 2.5% scores below 70 (intellectually disabled)
• Wechsler tests give separate Verbal IQ and Performance IQ scores

Worked Examples

**Example 1: Calculating IQ** A student has a chronological age of 8 years and mental age of 10 years. Calculate the IQ.

*Solution:* IQ = (MA ÷ CA) × 100 IQ = (10 ÷ 8) × 100 IQ = 1.25 × 100 IQ = 125

The child has superior intelligence (110-120 range, actually above at 125).

**Example 2: Finding Mental Age** A child aged 12 years has an IQ of 75. What is the mental age?

*Solution:* IQ = (MA ÷ CA) × 100 75 = (MA ÷ 12) × 100 75 ÷ 100 = MA ÷ 12 0.75 × 12 = MA MA = 9 years

The child functions intellectually like an average 9-year-old.

**Example 3: Interpreting Test Results** Ravi scores 95 on an IQ test. What does this indicate?

*Solution:* An IQ of 95 falls within the normal/average range (90-110). Ravi has typical cognitive abilities for his age and should be able to handle regular classroom instruction without special provisions for giftedness or learning disability.

Common Mistakes

• **Treating IQ as fixed and unchangeable** → Intelligence can be influenced by environment, education, nutrition, and stimulation. IQ scores can change over time.

• **Confusing Mental Age with actual knowledge** → Mental Age reflects cognitive functioning level, not what the child has been taught. A child with low MA can still learn when given appropriate instruction.

• **Believing one IQ test measures all intelligence** → IQ tests primarily measure logical-mathematical and linguistic abilities. They miss creative, practical, emotional, and bodily-kinesthetic intelligences identified by Gardner.

• **Using IQ to label or track students permanently** → Teachers should use intelligence assessment as one input among many, not as a permanent label that limits educational opportunities.

• **Ignoring cultural bias in testing** → Traditional IQ tests favour children from educated, urban, English-speaking backgrounds. Culture-fair tests like Raven's Matrices partially address this but no test is completely bias-free.

Quick Reference

• **IQ Formula:** (Mental Age ÷ Chronological Age) × 100

• **Average IQ = 100; Normal range = 90-110**

• **Binet-Simon (1905) = first test; Stanford-Binet (1916) = introduced IQ term**

• **Wechsler tests: WAIS (adults), WISC (children 6-16), WPPSI (preschool)**

• **Raven's Progressive Matrices = non-verbal, culture-fair**

• **IQ tests have limitations: cultural bias, narrow focus, not measuring all intelligences**