Human Growth and Development

Factors Influencing Intelligence The nature vs. nurture debate has evolved, with research showing that both genetics and environment shape intelligence. ●​ Genetics influence brain structure, memory, and cognitive abilities. Identical twins, who share 100% of their genes, tend to have more similar IQs than fraternal twins. ●​ Environmental factors, such as nutrition, education, and life experiences, also play a crucial role. Studies of adopted children show their IQs align more closely with their adoptive parents, emphasizing the impact of upbringing. ●​ Twins raised apart demonstrate how different environments create IQ differences, even in genetically identical individuals. Overall, genetics provide potential, while the environment determines how much of that potential is realized. Reaction Range The reaction range concept suggests that genes set upper and lower limits on intelligence, but environment influences where a person falls within that range. ●​ Example: A plant’s growth potential is determined by its genetics, but sunlight, water, and nutrients determine how much it actually grows. ●​ A child with high genetic potential may not fully develop their abilities if they lack education, stimulation, or emotional support. This theory highlights that intelligence is flexible, shaped by both inherited abilities and life experiences. Measurement and Development IQ tests assess cognitive abilities through tasks involving reasoning, memory, and problem-solving. Common IQ tests : ●​ Stanford-Binet Intelligence Scale ●​ Wechsler Adult Intelligence Scale (WAIS) The results are often represented by an Intelligence Quotient (IQ) score, which compares a person's mental age, based on their test performance, to their chronological age. The IQ score is calculated by dividing mental age by chronological age and multiplying by 100. For example, a child with a mental age of 12 and a chronological age of 10 would have an IQ of 120: (12 ÷ 10) × 100 = 120. However, IQ tests have limitations: ●​ They do not capture all aspects of intelligence. ●​ Some tests may be culturally biased . ●​ They are most useful when combined with other assessments.

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