Role of Heredity and Environment

About this chapter

Role of Heredity and Environment asks one question that every upper-primary teacher of ages 11-14 must answer: when an adolescent in class 7 learns Mathematics faster than her bench-mate, is the cause her genes, her surroundings, or both? The chapter walks through six ideas — meaning of heredity (sum total of traits in the fertilised ovum, zygote with 46 chromosomes, 23 from each parent, ~40-100 genes per chromosome, definitions by Peterson, Douglas and Holland, F.L. Ruch); meaning of environment (Anastasi, Douglas and Holland, Gilbert — physical, social, moral, economic, political, cultural and emotional forces); arguments in favour of heredity (twin studies by Thorndike, Newman, Freeman, Winfield — IQ correlation 0.90 for identical twins, 0.70 fraternal, 0.50 siblings, 0.31 parent-child, 0.30 unrelated); arguments in favour of environment (Freeman's 71-children study, James-Reece's hill-village twin study with 19-point IQ gap); the relative significance formula H x E x T = DL (Ross), Woodworth's view, Landis-Landis, Murphy, MacIver and Page; and educational implications for the upper-primary classroom — knowing the learner's background, varied teaching methods, guidance and counselling. CTET Paper 2 tests this as recall of definitions, correct attribution of twin-study numbers to the right researcher, application of the H x E x T formula to adolescent classroom situations, and pedagogy questions on planning teaching for ages 11-14 with mixed heredity-environment profiles. The four tests — Practice 15, Quiz 15, Hard 15, Mastery 30 — cover all six sections at CTET depth.