“Left-Brained or Just Misunderstood?” How to Write a Top-Band AQA Psychology Essay on Localisation & Lateralisation (16 Marks)
So, you’re revising Biopsychology and you see this 16-marker pop up:
Kieran completes a quiz and says, “I’m left-brained — that’s why I’m good at language!”
Sam laughs: “That’s silly — the whole brain works together!”
And the question is:
Discuss research into localisation of function in the brain and/or hemispheric lateralisation. Refer to Kieran and Sam’s discussion in your answer. (16 marks)
You freeze. What do they even want?
Let’s break it down, step-by-step, with a clear model essay and commentary on what earns top marks for AO1 (knowledge), AO2 (application), and AO3 (evaluation using PBWC).
✍️ First: What Does a Level 4 Answer (13–16 marks) Need?
| AO | What you must show |
|---|---|
| AO1 (6) | Accurate and detailed knowledge using specialist terms |
| AO2 (4) | Clear links to Kieran and Sam — not just name-dropping |
| AO3 (6) | Well-developed discussion using PBWC (Point, Because, Why, Counterargument) |
Let’s see what that looks like in action 👇
🧠 AO1 – Brain Knowledge: Localisation & Lateralisation
Student Response:
Localisation of function is the idea that specific areas of the brain are responsible for specific functions. For example, the frontal lobe is involved in movement and decision-making, the parietal lobe processes sensory information, the occipital lobe deals with vision, and the temporal lobe is responsible for hearing and memory. Within the frontal lobe of the left hemisphere, Broca’s area is responsible for speech production, while Wernicke’s area, found in the temporal lobe, is responsible for language comprehension.
Hemispheric lateralisation refers to how certain mental processes are mainly controlled by one side of the brain. For most people, the left hemisphere controls language, while the right hemisphere is more involved in spatial and emotional processing.
✅ Examiner Commentary:
This is strong AO1. The student explains localisation clearly and uses key brain regions (Broca’s, Wernicke’s, lobes) accurately. The mention of hemispheric lateralisation shows understanding of both required concepts. It’s also well-written, structured, and full of specialist vocabulary — exactly what examiners want for 6/6.
👥 AO2 – Application: What’s Going On With Kieran and Sam?
Student Response:
Kieran is partly correct in saying that the left brain is responsible for speech and language, because Broca’s and Wernicke’s areas are typically found in the left hemisphere. This reflects lateralisation of language functions. However, Sam is also right — it’s too simplistic to say someone is “left brained.” While language is mainly handled by the left hemisphere, the brain works as an integrated system. The corpus callosum allows both hemispheres to communicate, and the right hemisphere still plays a role in understanding tone, emotion, and non-verbal cues.
✅ Examiner Commentary:
This is a perfect example of AO2. The student links psychological theory to both Kieran and Sam’s arguments, using them as anchors to explore real brain function. The theory isn’t just “dropped in” — it’s explained through the scenario. Full marks for application.
💬 AO3 – Evaluation #1 Using PBWC
Student Response:
Point: One strength of localisation theory is that there is strong scientific evidence supporting it.
Because: For instance, Peterson et al. (1988) used brain scans to show that Broca’s area was active during speaking, and Wernicke’s area was active during listening.
Why: This supports the idea that language functions are localised in the brain and not spread evenly. It also makes the theory more credible because it is backed by objective, measurable data.
Counterargument: However, just because one area is active doesn’t mean it is the only area involved. Other brain regions may work in networks, so the idea of strict localisation could be oversimplified.
✅ Examiner Commentary:
This evaluation is textbook AO3. It’s structured using PBWC, which makes it easy to follow, fully developed, and balanced. The counterargument is thoughtful, and the student engages with the methodology and interpretation of brain scans. This is top-band writing.
💬 AO3 – Evaluation #2 Using PBWC
Student Response:
Point: A weakness of hemispheric lateralisation is that it is often exaggerated in pop psychology.
Because: Many people believe they are either “left brained” or “right brained”, which leads to stereotypes about personality and ability.
Why: This misrepresents the science. While some functions are more dominant in one hemisphere, most tasks use both sides working together, especially in healthy brains.
Counterargument: That said, split-brain research by Sperry does show real differences in function — for example, patients could name objects in the right visual field (left hemisphere) but not in the left visual field. So lateralisation is not a myth, just more nuanced than the media presents.
✅ Examiner Commentary:
Another excellent PBWC paragraph. The student begins with a real-world criticism, explains it, and justifies its importance for how psychology is understood. Then they add balance using research evidence — perfect for AO3.
Final Verdict: Why This Essay Is Level 4
| AO | What Was Done Well |
|---|---|
| AO1 (6/6) | Accurate, detailed and includes relevant brain structures and functions. Uses key terms correctly. |
| AO2 (4/4) | Excellent links to both Kieran and Sam, with thoughtful application of theory. |
| AO3 (6/6) | Two well-structured evaluation paragraphs using PBWC, with evidence, balance, and depth. |
Want to Write Like This Every Time?
If you liked how this essay was structured and explained, you’ll love the
👉 7-Day Psychology Essay Writing Course 👈
Inside the course, you’ll:
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Learn how to structure every essay using the PBWC method
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Finally feel confident tackling 16-mark essays
Remember:
Being “left-brained” or “right-brained” doesn’t determine your grade — but learning how to write with structure and clarity just might.
Happy essay writing!