Heredity and environment as factors of development

What this heading covers

A named heading on every track, and one of the few in the whole syllabus where the correct answer is almost always the same shape: not heredity, not environment, but the two interacting.

That makes it easy marks — provided you can also say what each one actually contributes, because the better questions ask exactly that.

The two factors

Heredity is what is transmitted from parents at conception, through the genes. It is fixed at that moment and cannot be altered afterwards.

Environment is everything that acts on the child from conception onwards — and that word begins earlier than most candidates assume. The mother's health and nutrition during pregnancy are environment, not heredity.

	Heredity	Environment
Fixed when	At conception	Acting continuously from conception on
Can it be changed?	No	Yes — this is why teaching matters
Supplies	Potential, limits, a range	Which point in the range is reached
Examples	Height potential, eye colour, blood group, temperament tendencies, intelligence potential	Nutrition, family, school, peers, language exposure, culture, economic condition

What each one supplies

The distinction the syllabus wants is potential against realisation.

• Heredity sets the range. A child inherits a span of possible heights, a span of possible cognitive attainment, a predisposition towards a temperament.
• Environment decides the point within that range. Nutrition, stimulation, schooling and affection move the child up that span; deprivation moves it down.

This is sometimes called the reaction range: the same inheritance produces different outcomes in different environments, and no environment moves a child outside their range altogether.

Two consequences the paper uses:

• Environment cannot exceed the range heredity allows. Teaching does not produce unlimited attainment.
• Heredity does not guarantee an outcome either. A strong inheritance in a deprived environment delivers little, which is the whole argument for early intervention.

Nature against nurture is not an open question here

Older textbooks frame it as a contest — which matters more? The syllabus treats that framing as outdated. The accepted position is nature through nurture: the two are not rivals but partners, and asking which contributes more is like asking whether length or width contributes more to the area of a field.

This is the single most reliable item in the heading. An option saying "heredity alone", "environment alone", or giving a percentage split is nearly always wrong; the option describing interaction is nearly always right.

The evidence

Teacher-education material presents the case through two kinds of comparison, and a question may name them.

• Identical twins reared apart share all their heredity and differ in environment. They remain markedly similar on many traits — which is the evidence for heredity — while differing in ways that track their separate upbringings, which is the evidence for environment. The same study supports both sides, and that is the point.
• Adopted children resemble their biological parents on some traits and their adoptive families on others, particularly language, habits, attitudes and attainment.
• Children raised in extreme deprivation show severe delay that partly recovers when the environment improves, and recovers less the longer the deprivation lasted — which connects to the critical period.

Treat the conclusion rather than the numbers: both factors are necessary, neither is sufficient.

The parts of the environment

The primary syllabus names environment as a factor in its own right, so it is worth separating.

Kind	Includes
Prenatal	The mother's nutrition, health, stress, illness, medication during pregnancy
Physical	Housing, sanitation, nutrition, climate, space to play
Social	Family, peers, neighbourhood, caste and community expectations
Cultural	Language, customs, beliefs, what the community values
Economic	Income, the resources a family can supply, whether the child must work
Educational	School, teacher, curriculum, materials, the classroom climate

The last row is the one that matters professionally: the school is the part of a child's environment a teacher controls. A teacher cannot change a child's heredity and cannot change most of their home, but the classroom is environment, and it is the part that is deliberately designed.

Why this heading is in a teaching paper at all

Because of what follows from it.

• No child is written off by inheritance. If heredity set outcomes alone, teaching would be pointless; the interactionist position is what makes a teacher's work meaningful.
• Differences in a class often have environmental causes. A child with less vocabulary may have had less talk addressed to them, not less capacity. Reading the gap as fixed ability is the error the syllabus guards against.
• Early intervention is justified. The earlier the environment improves, the more of the range is still reachable.
• Deficit thinking is rejected. Attributing a child's difficulty to their home or community and concluding that nothing can be done is the wrong answer whenever it appears.

The kind of question the paper sets

Which statement about heredity and environment is correct? (a) Heredity is more important than environment (b) Environment is more important than heredity (c) Both interact; heredity sets the limits and environment determines attainment within them (d) They contribute equally in all traits

(d) is the trap for candidates who know the answer involves both — "equally, in all traits" is a different and wrong claim.

A child from a home with few books and little conversation has a smaller vocabulary than classmates. A teacher should conclude that — (a) the child has low innate ability (b) the difference is largely environmental and can be reduced by rich language experience (c) nothing can be done until the home changes (d) the child should be placed in a lower section

(a) and (d) read an environmental gap as fixed capacity; (c) is deficit thinking.

The mother's nutrition during pregnancy is an example of — (a) heredity (b) maturation (c) environment (d) a genetic factor

Environment begins at conception, not at birth. This is the commonest single error in the heading.

Identical twins reared in different families remain similar in many traits. This is evidence that — (a) environment has no effect (b) heredity has a substantial influence (c) heredity determines everything (d) twins are a special case

(a) and (c) overreach from the same evidence; the differences between the twins are the evidence for environment.

Which is not a part of a child's environment? (a) The neighbourhood (b) The language spoken at home (c) Blood group (d) The classroom climate

The idea that the same inheritance produces different outcomes in different environments is called — (a) maturation (b) reaction range (c) readiness (d) the critical period

Mistakes that cost marks here

• Choosing heredity alone or environment alone when an interaction option is present.
• Choosing a percentage split, or "equally in all traits".
• Treating prenatal influences as heredity. Anything acting on the child, including before birth, is environment.
• Saying environment can raise a child beyond the range heredity allows — or that heredity delivers an outcome without a supporting environment.
• Deficit thinking: concluding that a child from a poor home cannot be helped at school.
• Reading twin evidence as supporting only one side. It supports both.
• Forgetting that the classroom is environment — the one part a teacher actually controls.

In one line

Heredity hands the child a range and environment decides where in that range they arrive, so the two are partners rather than rivals — and the part of the environment a teacher is responsible for is the only factor in the whole heading that can be changed on purpose.

In the classroom

The usable form of this heading is a question to ask about any struggling child: is this difference something the child brought, or something the child's circumstances produced? Most classroom gaps — vocabulary, general knowledge, confidence, familiarity with books — are the second kind, and the second kind responds to what happens in the room.