Heredity and Environment
Introduced| English | Meaning |
|---|---|
| genes/dʒiːnz/ | Sequences of DNA that carry information for functional products such as proteins or RNA molecules. |
| environment/enˈvaɪrənmənt/ | The surrounding conditions that affect an organism, system or activity. |
| Heredity/həˈredɪti/ | The transmission of genetic information and associated characteristics from one generation to the next. |
| Adoption studies/əˈdɒpʃn ˈstʌdiz/ | Adoption studies |
| evolutionary perspective/ɪvəˈluːʃənəri pəˈspektɪv/ | An approach explaining behaviour and mental processes partly through natural selection and inherited adaptations. |
| natural selection/ˈnætʃərəl sɪˈlekʃn/ | The process in which inherited traits that improve survival and reproduction become more common in a population over generations. |
| Twin studies/twɪn ˈstʌdiz/ | Twin studies |
| Family studies/ˈfæmɪli ˈstʌdiz/ | Family studies |
Two identical twins, two different lives
- Identical twins share the same genes 基因, yet they never turn out exactly the same.
- Something other than genes must be acting on them.
- That something is environment 环境 — everything that happens to a person.
Heredity and environment interact
- Heredity 遗传 is what is passed down biologically from parents.
- The CED's claim is that the two interact — neither works alone.
- Height is inherited, but poor nutrition lowers it. The gene sets a range; the environment picks a point inside it.
Twin and adoption studies 收养研究 separate the effects of genes and environment
Heredity, environment, or the interaction?
Sort each piece of evidence by what it points to.
The CED's position on heredity and environment is that they...
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Heredity and environment interact; the gene sets a range and conditions pick a point inside it.
The evolutionary perspective
- The evolutionary perspective 进化论视角 asks how natural selection 自然选择 shaped behaviour.
- A behaviour that helped ancestors survive and reproduce is more likely to appear today.
- Fear of snakes is learned unusually fast — plausibly because slow learners left fewer descendants.
The ____ perspective explains behaviour by asking what helped ancestors survive and reproduce.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
The evolutionary perspective applies natural selection to behaviour and mental processes.
Never write that a trait is "caused by genes" or "caused by upbringing". The CED's position is that heredity and environment interact, and an exam answer that picks one side has taken a position the course rejects.
Select all the research designs the CED names for separating heredity from environment.
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Twin, adoption and family studies vary how much DNA and how much environment people share.
Match each design to what it varies.
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Each design holds one thing constant and varies the other, so the two sources can be told apart.
How researchers separate the two
- Twin studies 双生子研究 compare identical twins with fraternal twins.
- Adoption studies compare children with their biological and adoptive parents.
- Family studies 家族研究 track a trait through relatives who share different amounts of DNA.
If identical twins raised apart are still similar on a trait, that points to heredity.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Same genes, different environments — so the remaining similarity is evidence for heredity.
Reading a twin study
- If identical twins raised apart are still alike on a trait, heredity matters for it.
- If identical twins raised together differ, environment matters for it.
- Neither result ever proves that one side acts alone — it only shows how much each contributes.
Two brothers are both tall. Their father is tall, so heredity contributes. But the younger brother, who grew up after the family's income rose, is 5 cm taller than his sibling — environment picked a different point inside the same inherited range.
Heredity and environment always interact. The evolutionary perspective explains behaviour by what helped ancestors survive. Twin, adoption and family studies are how psychologists estimate how much each side contributes.
Write from a vocabulary gap of 18 points
- Identical twins were raised apart. One studied vocabulary for 12 hours a week and scored 18 points higher than the co-twin.
- Say what heredity and environment each explain.
Identical twins raised apart differ by 18 vocabulary points. The higher scorer studied 12 hours a week. What can heredity and environment each explain?
Identical heredity with different rearing is one of the designs used to separate the two contributions.
What does the 18-point gap show?
Difficulty 1/5 · 100 coins + a small bonus on first completion today
The study time differs, so environment is still part of the 18-point gap.