In one line: The nervous system and the body change across the whole of life, and behaviour changes with them.
A fifteen-year-old and a thirty-year-old are offered a dare. The fifteen-year-old is more likely to take it, above all when friends are watching.
Nothing has been taught to the adult that the teenager lacks. The difference lies largely in the brain itself: biological change has taken place in between.
Remember: A behaviour that changes with age may be a body that is changing.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it with your first topic free to keep:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Key idea: Four processes produce biological change. Two unfold from within, and two respond to what happens to a person.
Sources of biological change
Maturation
Development that follows a biological timetable (maturation).
The areas at the front of the brain, used for planning and self-control, are the last to mature.
Neuroplasticity
The brain's connections are strengthened by use and weakened by disuse (neuroplasticity).
Unused connections are removed, which makes the remaining ones faster.
Hormones
Hormones released at puberty act on the brain as well as the body.
The brain's reward system becomes more sensitive before self-control has caught up.
Recovery after injury
After a stroke, undamaged areas can take over some lost functions.
Recovery depends on intensive practice, which is neuroplasticity put to work.
Maturation · Plasticity · Hormones · Recovery
The dare makes sense now. In mid-adolescence, a reward system sharpened by hormones is paired with self-control that is still maturing. Two biological changes, moving at different speeds, produce a period of greater risk taking.
Exam tip: Link each process to a change in behaviour and to a time.
Maturation explains why a behaviour changes with age. Plasticity explains why it changes with experience.
Memorize terms 3x faster
Smart flashcards show you cards right before you forget them. Perfect for definitions and key concepts.
Key idea: Biological change differs in its speed, in its cause and in when it is possible at all.
Gradual change
- Maturation across childhood and adolescence
- Skill built up through practice
- Slow decline of some abilities in old age
Sudden change
- A stroke or a head injury
- A rapid shift in hormone levels
- The effect of a drug on mood
Timing matters as well as speed. For some abilities the brain is especially ready to change during a limited window, a sensitive period. Children pick up the sounds of a language far more easily than adults do.
The stronger claim, that an ability cannot develop at all once the window has closed, is called a critical period. For most human abilities the evidence supports the weaker claim.
Planned and unplanned: Puberty is expected. A stroke is not. Training and medication are change brought about on purpose.
Classifying a change in this way is a quick piece of analysis in an essay.
Key idea: Biological explanations raise an old question: are we free to change, or are we determined?
Biological determinism holds that behaviour is fixed by genes, brain structure and hormones. On this view, the teenager who takes the dare could not have done otherwise.
The case for it
- Maturation follows a timetable set by genes
- Damage to the front of the brain can alter personality
- Hormones change mood and drive
The case against it
- Experience reshapes the brain
- The same genes lead to different outcomes in different environments
- People reflect, choose and act: agency
Most psychologists hold a middle position. Biology makes some behaviours more likely at some ages, and sets limits. Within those limits, experience and a person's own agency decide the outcome.
The position matters outside the classroom. If risk taking were fully determined, there would be no point in driving lessons, and no sense in holding anyone responsible.
Remember: More likely is not the same as inevitable.
Know your predicted grade
Take timed mock exams and get detailed feedback on every answer. See exactly where you're losing marks.
How this is asked: On Paper 1, one 15-mark essay links a concept to a context, often as a claim to discuss. Change fits the context of human development especially well.
Details of studies are not assessed. Conceptual understanding and critical thinking are.
The essay pattern
- State a position on the claim.
- Explain the biological change that supports it, and the behaviour it changes.
- Show the limit of that explanation with a second process.
- Bring in determinism and agency.
- Conclude with a position you have argued for.
The trap: biology against environment: Treating the two as rivals misses the point of neuroplasticity.
Experience changes the brain, so an environmental cause becomes a biological change.
One claim in the psychology of human development is that the behaviour of adolescents is determined by the maturing brain. Discuss this claim with reference to change.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.