IB Psychology Extended Essay

The criteria on this page are the ones for exams from May 2027, when the Extended Essay is marked out of 30. See what changed. If you sit your exams in November 2026, the older 34-mark criteria are summarised after them.

The IB Psychology Extended Essay is a 4,000-word argument built on published psychological research. That definition rules out the two things students most often try to write instead: an experiment of their own, and an essay of interesting opinions about the mind. The Psychology EE is a literature-based investigation: your originality lives in the question you pose and in how critically you select, compare and evaluate real studies to answer it. This guide explains how the five EE criteria play out in Psychology, which research questions work, how to engage with studies like a researcher rather than a fan, and the mistakes that most often drag essays into the middle bands.

What a Psychology EE is, and is not

Through November 2026 the Psychology IA is an experiment based on a published study, with your own participants, data and statistics; from May 2027 it is a research proposal. The EE is the opposite arrangement: it must be based on secondary sources only, and collecting your own data is not permitted. If the IA is about doing psychology (see our IB Psychology IA guide), the EE is about judging psychology: weighing methods, samples and conflicting findings until a defensible answer to your question emerges. The other thing the EE is not: pop psychology. Claims sourced from blogs, talks and self-help books have no evidential standing in this essay.

Choosing a research question for a Psychology EE

A strong Psychology EE research question has four characteristics:

Anchored in a real literature: Published, peer-reviewed studies exist on both sides of the question, giving you material to evaluate.
Defined constructs: The behaviour and the population are specific enough to be measured, not "the brain", "happiness" or "people" in general.
Evaluative: "To what extent does the evidence support…" phrasing that makes weighing studies the whole task.
Genuinely contested: If every study agrees, there is nothing to argue; disagreement in the literature is your raw material.

Examples of strong Psychology EE research questions

To what extent does post-event information distort eyewitness memory of a witnessed event? Why it works: it sits on a large experimental literature, and it invites evaluation of how far laboratory findings generalise to real witnesses.
To what extent does the evidence support a causal link between heavy social-media use and depressive symptoms in adolescents? Why it works: it builds the correlation-versus-causation distinction into the question, and the literature contains genuinely conflicting findings to weigh.
To what extent do conformity effects observed in laboratory experiments generalise across cultures? Why it works: it sets classic findings against later cross-cultural work, so critical comparison is not an add-on but the essay itself.

Weak research questions, and why they fail

Why do people dream? Why it fails: the question is too broad and the candidate explanations are largely speculative, so the essay drifts into summarising theories, or pop psychology, with nothing concrete to evaluate.
Does music affect the brain? Why it fails: "music", "affect" and "the brain" are all undefined. Almost any finding counts as evidence for something, which means no focused argument is possible.

How the five EE criteria play out in Psychology

From May 2027, every Extended Essay is marked out of 30 on five criteria. In Psychology they reward the following:

Criterion A: Framework for the essay (6 marks). A precise psychological question, a visible method for a literature-based essay (how you found and selected studies, and why these studies and not others) and a structure organised to answer the question rather than to tour the topic.
Criterion B: Knowledge and understanding (6 marks). Accurate reporting of theories and studies (their aims, methods and findings), using psychological terminology correctly.
Criterion C: Analysis and line of argument (6 marks). Analysis that connects the studies into a coherent argument about the question, with findings that stay relevant to it.
Criterion D: Discussion and evaluation (8 marks). The highest-weighted criterion and the real test. It rewards evaluation of the studies you cite (their samples, designs, measures, generalisability and cultural bias), a balanced discussion that weighs conflicting results instead of listing supportive ones, and an evaluation of the essay's own limits. Describing ten studies scores worse than critically comparing five.
Criterion E: Reflection (4 marks). Marked on the reflective statement in your RPF. Strong reflection evaluates, with specific examples, how your thinking changed as you read, such as a study that undermined your assumed answer, rather than keeping a diary of the workload.

If you sit your exams in November 2026, the essay is marked out of 34 instead: Focus and method (6), Knowledge and understanding (6), Critical thinking (12), Presentation (4) and Engagement (6, marked on the three RPPF reflections). The advice above carries over, because research, analysis, and discussion and evaluation together make up Critical thinking.

Working with real studies, critically

The evidence base of a Psychology EE is peer-reviewed research: journal articles and the studies discussed in academic textbooks. For each study that carries weight in your argument, examiners expect more than an abstract-level summary. Who were the participants, and how far do they represent the population in your question? What was actually measured, and is it a fair proxy for the behaviour you care about? Was the design experimental or correlational, and are you drawing only the conclusions that design permits? A correlational study can never, by itself, support a causal claim, and essays that respect that line consistently read as more credible.

Treat classic studies with respect but not reverence. Psychology as a discipline has spent recent years re-examining how well famous findings replicate, and a top-band essay reflects that maturity: it asks whether a result has been reproduced, at what scale, and in which populations, rather than treating one dated experiment as settled fact. Balance older foundational work with more recent research where you can. And keep pop psychology out entirely: recycled myths such as "we only use ten per cent of our brains", or personality claims from online quizzes, tell an examiner that the essay cannot separate evidence from folklore.

Common mark-losing mistakes in Psychology EEs

The annotated list: a parade of study summaries with no argument connecting them. Coverage without evaluation caps Criteria C and D.
Describing instead of evaluating: reporting what each study found but never assessing its sample, method or measures.
Pop-psych sourcing: building claims on blogs, talks or self-help books instead of peer-reviewed research.
Correlation treated as causation: a common logical error, and one examiners are quick to spot.
Cherry-picking: citing only studies that support the thesis and ignoring the contradicting literature your question exists to weigh.
Overclaiming in the conclusion: a confident verdict the mixed evidence cannot carry. A calibrated "the evidence partly supports…" answer scores better than false certainty.

Frequently asked questions

Can I run my own experiment for a Psychology EE?

No. A Psychology EE must be based on secondary sources only, and collecting primary data is not permitted. Your originality comes from the argument you build: how you select, compare and evaluate existing studies to answer a focused question.

How many studies should a Psychology EE discuss?

Enough to sustain an argument, each evaluated properly: often a core of several studies examined in depth. Listing many studies descriptively scores worse than critically comparing a smaller set, because the criteria reward evaluation, not coverage.

How is the Psychology EE different from the Psychology IA?

Through November 2026 the IA is an experiment based on a published study, with your own data and statistics, and from May 2027 it is a research proposal. The EE is a 4,000-word argumentative essay built on published research, with no data collection of your own.

Grade your Psychology EE before you submit

IBLens analyses Extended Essays against the published criteria for your exam session and shows you, criterion by criterion, where marks are being lost, including the Psychology classics: description without evaluation, and causal claims the evidence cannot support. Paste a draft into the Extended Essay grader, where the first preview is free, to see where your Psychology EE stands, and read the complete IB Extended Essay guide for the full process from question to final reflection.

An AI check is outside help on your EE, so ask your supervisor before you use IBLens or any other tool, and tell them if you do.

Grade your Psychology EE with IBLens