IB Psychology · Paper 1 guide

IB Psychology Paper 1 (2027): how each section is marked, with worked answers

IB Psychology Paper 1 is 1 hour 30 minutes and 35 marks: two 4-mark short answers (Section A), two 6-mark questions applying psychology to an unseen scenario (Section B) and one 15-mark concept essay chosen from two (Section C). It is 35% of the grade at SL and 25% at HL.

Checked against the IB Diploma Psychology guide (first assessment 2027) — October 2026

Paper 1 at a glance

Section	What you do	Marks	Suggested time
A	Two compulsory short answers: describe or explain a content point and give one example	2 × 4 = 8	about 20 min
B	Two compulsory questions applying what you know to an unseen scenario set in a context	2 × 6 = 12	about 30 min
C	One extended response from a choice of two, linking a context to one of the six concepts	15	about 40 min

Total 35 marks in 1 hour 30 minutes. Weighting: SL 35%, HL 25%. Suggested times are our split of 90 minutes by marks (about 2.5 minutes a mark), not an IB rule.

Section A: the 4-mark short answers

Each question asks you to describe or explain one content point and give one example. The 4 marks are two separate halves: up to 2 for the content and up to 2 for the example. A perfect content paragraph with a bare, unexplained example still loses half the marks.

The two bands, in plain words

1–2Limited knowledge. An example is mentioned, but how it shows the content point is left for the examiner to work out.

3–4Detailed, relevant knowledge of the content point, and an example that is explained, with the link to the point stated outright.

Worked example

Our practice question: Explain how one hormone may influence human behaviour. Use one example in your answer. [4]

First attempt2 / 4

Oxytocin is a hormone that affects behaviour, especially trust and bonding. For example, Kosfeld et al. (2005) gave male participants oxytocin or a placebo through a nasal spray, and then they played an investment game.

Why 2: the content is accurate but thin (no mechanism), and the example is all procedure. Procedure earns nothing; the example never says what was found or how that shows oxytocin influencing behaviour.

Rewrite4 / 4

Oxytocin is a hormone released from the pituitary gland that can increase social approach behaviour, such as trusting others, possibly by reducing anxiety about social risk. For example, Kosfeld et al. (2005) found that participants given oxytocin were more willing to hand money to a stranger in a trust game than those given a placebo. This shows oxytocin influencing behaviour because the only planned difference between the groups was the hormone, and it changed how much risk they would take on another person.

The one change: the highlighted sentence. It says what the example shows and ties it back to the content point, which is what the example half of the marks is for.

Section B: applying psychology to an unseen scenario

You get a short scenario set in one of the four contexts and two 6-mark questions on it. The scenario is the point. An answer that explains the theory correctly but never uses the details of the scenario cannot reach the top band.

The three bands, in plain words

1–2Limited knowledge; the link to the scenario is relevant but thin.

3–4Mostly accurate knowledge with some detail; the application is relevant but only partly developed.

5–6Accurate, detailed knowledge, and an application that is well developed and built from the specifics of the scenario.

Worked example

Our practice scenario (health and well-being): Maya is 16. Most of her close friends started vaping last term and often post videos of it. Maya’s older cousin, whom she admires, also vapes. Maya has begun vaping at parties, where her friends cheer when she joins in.

Question: Explain how social learning could account for Maya’s behaviour. [6]

First attempt3 / 6

Social learning theory (Bandura) says behaviour is learned by observing models. There are four processes: attention, retention, reproduction and motivation. Behaviour is more likely to be copied if the model is similar or high status, and if the behaviour is reinforced. This explains why Maya vapes.

Why 3: the theory is accurate, but the scenario appears only in the last sentence. None of Maya’s details (her friends’ videos, the cousin, the cheering) is used.

Rewrite6 / 6

Social learning theory says behaviour can be learned by observing models and copying what is rewarded. Maya’s friends are models she identifies with because they are her age and group, and their videos make vaping something she repeatedly attends to and remembers. Her older cousin adds a high-status model she admires. At parties she can reproduce the behaviour, and the cheering is direct reinforcement, while seeing her friends praised online was vicarious reinforcement. Together these make her more likely to keep vaping.

The one change: each part of the theory is attached to a specific detail of the scenario, instead of the theory and the scenario sitting side by side.

Section C: the 15-mark concept essay

You choose one of two questions. Each asks you to connect an area of study in a context to one of the six concepts: bias, causality, change, measurement, perspective or responsibility. The content and the named concept both have to be there. An essay that explains stress and health well but treats “causality” as a word in the title stays in the middle bands.

The five bands, in plain words

1–3Barely engages with the question; describes rather than argues; no real link to the concept.

4–6Relevant material, described rather than analysed; the concept link is stated but only partly relevant; a simple conclusion.

7–9Understands what is asked but answers it in part; analysis present but undeveloped; the conclusion doesn’t always follow.

10–12Answers the question; analysis present though not fully developed; the concept link is explained; the conclusion follows from the argument.

13–15Answers the question fully; sustained, developed analysis; the concept runs through the whole essay; precise terminology and a reasoned conclusion.

Worked example: one paragraph at two levels

Our practice question: To what extent does the concept of causality limit what research can tell us about stress and physical health? [15]

Middle-band paragraphreads like 4–6

Kiecolt-Glaser et al. (1984) took blood samples from medical students a month before their exams and during their exams. They found that natural killer cell activity was lower during the exams. This shows that stress weakens the immune system, so stress is bad for physical health.

What holds it back: the study is described, then the conclusion claims cause and effect, which is exactly what the question asks you to question. Causality never appears.

Top-band paragraphreads like 13–15

Kiecolt-Glaser et al. (1984) found lower natural killer cell activity in medical students during exams than a month before, which suggests stress suppresses immune function. However, this is a natural experiment: exams were not assigned at random, and students may also sleep less and eat differently at exam time, so these are rival causes the design cannot rule out. The finding therefore supports a link between stress and immunity more strongly than it shows that stress alone causes the change. This matters for the question, because much stress–health research shares this limit, so causality narrows what it can claim without making it useless.

The one change: the finding is tested against the concept (what would have to be true for it to show cause?) and the paragraph ends with a judgement that answers “to what extent”.

Marks shown on this page are our own illustrative marks against the bands above. The bands are our plain-English wording of the IB’s structure, not the IB’s markband text. Practice questions and answers are written by Markaroo.

Where Paper 1 marks are lost

Section A: describing a study’s procedure. Specific details of research studies are not assessed here. A study earns marks through what it found and how that shows the content point.
Section A: a bare example. Naming an example without saying how it shows the point caps the example half at 1–2.
Section A: two examples. Only the first example is marked. Pick your best one and explain it.
Section B: theory first, scenario last. If you could paste the answer under a different scenario, it hasn’t applied anything. Use the scenario’s details in every step.
Section C: content without the concept. The concept is half the question. Bring it into every paragraph, not just the introduction.
Section C: a conclusion that doesn’t follow. “To what extent” needs a judgement that comes out of the argument you made.

Paper 1 questions

How long is IB Psychology Paper 1?

1 hour 30 minutes for 35 marks. It is 35% of the final grade at SL and 25% at HL, and both SL and HL students sit the same Paper 1.

How many questions do you answer in Paper 1?

Five: two 4-mark short answers in Section A, two 6-mark scenario questions in Section B, and one 15-mark essay in Section C, chosen from two.

Do I need to memorise study details for Paper 1?

Not the procedures. The guide says knowledge of specific details of research studies is not assessed in Sections A and C. What earns marks is knowing what a study found and explaining how that supports the point you are making.

Are there past papers for the 2027 Paper 1?

No. The first exams under the new guide are in May 2027, so there are no past papers in this format yet. Older IB Psychology papers follow a different structure and will not match how Paper 1 is now marked.

Can Markaroo mark my Paper 1 answers?

Yes. Each answer is marked against the band ladder for its question type (Section A, B or C), with a mark, the reason for it and the one change that moves it up. The free plan includes 2 written answers marked free.