Studying Development
Introduced| English |
|---|
| Developmental psychology/dɪˈveləpmentl saɪˈkɒlədʒi/ |
| longitudinal study/ˌlɒŋɡɪˈtjuːdɪnl ˈstʌdi/ |
| cohort effect/ˈkəʊhɔːt ɪˈfekt/ |
| cross-sectional study/krɒs ˈsekʃənl ˈstʌdi/ |
Two ways to watch a person change
- You can follow one group of people for twenty years.
- Or you can test people of many ages on the same afternoon.
- Both answer "how do people change?" — and each buys the answer at a different price.
What developmental psychology studies
- Developmental psychology 发展心理学 studies change across the lifespan.
- It works both chronologically — birth, infancy, childhood, adolescence, adulthood — and thematically.
- The enduring themes cut across ages: stability and change, nature and nurture, and continuous versus discontinuous development.
Select all the enduring themes the CED names in developmental psychology.
Recall and recognition belong to memory, not to developmental themes.
Longitudinal research
- A longitudinal study 纵向研究 follows the same people over time.
- It shows genuine change within individuals, which is what a developmental claim needs.
- The costs: it takes years, and people drop out — often not at random.
Longitudinal or cross-sectional?
Sort each feature by the design it belongs to.
A longitudinal study is the only design that can show...
Following the same people is what makes within-person change measurable.
A cohort effect is not a small technical caveat. If 70-year-olds score lower on a technology task than 20-year-olds in a cross-sectional study, the honest reading is that they grew up in a different world, not that ability declines with age.
The confound in cross-sectional research, where age groups also differ by generation, is the ____ effect.
The cohort effect means the groups grew up in different worlds, not only at different ages.
Cross-sectional research is faster than longitudinal research.
It tests everyone at once, which is exactly why it cannot separate age from generation.
Cross-sectional research
- A cross-sectional study 横断研究 compares different age groups at one time.
- It is fast and cheap, and gives an answer this month rather than in 2045.
- The cost is the cohort effect 同辈群体效应: the groups differ by generation as well as by age.
Match each design to its main cost.
Each design buys one thing and pays for it with another.
Choosing between them
- If the question is whether a person changes, only a longitudinal design can answer it.
- If the question is how age groups differ right now, cross-sectional is enough.
- An exam answer names the design and the cost that comes with it.
A cross-sectional study finds older adults use fewer digital services. A longitudinal study of the same people over ten years finds their use rising. Both are correct: the first measured a cohort difference, the second measured change.
Developmental psychology works chronologically and thematically. A longitudinal study follows the same people — slow, but it measures real change. A cross-sectional study compares age groups at once — fast, but confounded by the cohort effect.