The Multi-Store Model (MSM)

Memory works as three separate stores: Sensory Register, Short-Term Memory (STM) and Long-Term Memory (LTM).

• Sensory Register: holds info from your senses for under half a second, huge capacity, mostly unattended info decays fast.
• STM: capacity is 7 plus or minus 2 items (Miller), duration is about 18-30 seconds without rehearsal, coding is mainly acoustic (sounds).
• LTM: capacity is potentially unlimited, duration can be a lifetime, coding is mainly semantic (meaning).
• Info moves from STM to LTM through maintenance rehearsal (repeating it over and over).
• Common mistake: students say STM and LTM are the same store just used differently. They are structurally separate with different coding, capacity and duration.

Capacity, Duration and Coding

• These three features are tested with the same core studies each year, so learn the numbers exactly.
• Miller (1956): STM capacity is 7 plus or minus 2 chunks.
• Peterson and Peterson: STM duration without rehearsal is about 18-30 seconds, tested using trigrams and a counting-backwards task to stop rehearsal.
• Bahrick: LTM duration can last up to 48 years, shown using photo recognition of old school friends.
• Common mistake: mixing up which store is acoustic and which is semantic. STM = sounds, LTM = meaning.

Forgetting

Two main explanations are on the AQA spec.

• Interference theory: forgetting happens because memories compete or become confused with each other.
• Proactive interference: old learning disrupts new learning.
• Retroactive interference: new learning disrupts old learning.
• Retrieval failure: forgetting happens because the right cues are not available at recall, even though the memory is still stored. This links to context-dependent forgetting (wrong environment) and state-dependent forgetting (wrong mood or physical state).
• Common mistake: confusing proactive and retroactive interference direction. Use PO-RN: Proactive = Old disrupts new, Retroactive = New disrupts old.

The Cognitive Interview

A police technique to improve eyewitness recall accuracy, made of four main components:

• Report everything, even small or seemingly irrelevant details.
• Reinstate the context of the original event mentally.
• Reverse the order of events from the incident.
• Change perspective, recalling from another person's viewpoint.

Eyewitness Testimony

• Loftus and Palmer studied how leading questions distort memory, showing that the verb used in a question (for example smashed versus hit) changes estimated speed and can create false memories of details like broken glass.
• Anxiety can affect the accuracy of eyewitness testimony, and can either improve or reduce accuracy depending on the study and context (tunnel theory versus weapon focus).
• Common mistake: assuming eyewitness testimony is always unreliable. The spec expects you to discuss factors that increase AND decrease accuracy.

Exam Tip

Always use the exact key terms (coding, capacity, duration, interference, retrieval failure, cues) in your answers, and back up explanations with the correct named study.

What perception is

Perception is how the brain organises and interprets raw information from the senses (mostly vision) into something meaningful. It is different from sensation, which is just the raw data hitting your eyes, ears etc. Perception is a constructive, top-down as well as bottom-up process, meaning the brain does not just passively receive an image, it actively builds one using clues.

Depth cues

We live in a 3D world but the retina only receives a 2D image, so the brain uses depth cues to work out distance.

• Monocular cues (need only one eye): height in plane (things higher up in a scene look further away), relative size (smaller objects look further away), occlusion (an object blocking another is seen as nearer), linear perspective (parallel lines like railway tracks appear to converge with distance).
• Binocular cues (need both eyes): retinal disparity (each eye gets a slightly different image, the brain compares them to judge depth), convergence (the eyes turn inward more for close objects, less for far ones).

Visual illusions

Illusions show that perception can be tricked, proving it is not a direct copy of reality.

• Ambiguous figures: an image that can be seen two ways, such as the Necker cube or the Rubin vase (face/vase).
• Fiction (illusory contours): the brain perceives edges or shapes that are not actually drawn, such as the Kanizsa triangle.
• Size constancy failures, for example the Ponzo illusion and the Müller-Lyer illusion, where two identical lines look different lengths because of misleading depth cues.

Explanations of perceptual organisation

• Gregory's constructivist theory: perception is mostly top-down, we use past experience and expectation to make a 'best guess' at what we are seeing, which is why illusions fool us.
• Gibson's direct theory (nature side): perception is mostly bottom-up, we pick up enough information straight from the environment (optic flow, texture gradient) without needing past experience.

Factors affecting perception

• Perceptual set: expectation, motivation, emotion and culture can all bias what we perceive before we consciously notice it.
• Visual cues can be combined and sometimes conflict, causing errors in judgement.

Common mistakes

• Mixing up sensation and perception, always define both if asked to compare.
• Confusing monocular with binocular cues, learn which cue belongs in which list.
• Forgetting illusions are evidence FOR a theory, always link an illusion example back to Gregory or Gibson in an evaluation answer.
• Not naming the specific illusion (Ponzo, Müller-Lyer, Kanizsa, Necker cube, Rubin vase) when asked for an example, generic answers lose marks.

Brain development from birth

The brain is not fully formed at birth. Babies are born with roughly 100 billion neurons, but the connections between them (synapses) are what really matter for learning. In the first three years synapse formation happens at huge speed, this is called synaptic connectivity or synaptogenesis.

Synaptic pruning

After this rapid growth the brain does not keep every connection. Synaptic pruning removes connections that are not used, following the rule 'use it or lose it'. Connections that are used often become stronger and faster (myelination helps this), while unused ones are pruned away. Pruning continues through childhood and adolescence, especially in the frontal lobe.

The frontal lobe and adolescence

The frontal lobe is responsible for decision-making, impulse control, planning and reasoning. It is one of the last brain areas to fully develop, not maturing until the early-to-mid twenties. This is a key idea in GCSE Psychology because it explains typically 'risky' teenage behaviour, it is not that teenagers are careless, it is that the brain region controlling impulse control is still developing.

Blakemore and Choudhury (2006)

This is the key study for this topic. Blakemore and Choudhury reviewed research on brain development and concluded that the prefrontal cortex continues to develop during adolescence, which affects risk-taking, decision-making and social/emotional processing. Their work links directly to real-life applications, such as why the legal system treats young offenders differently and debates about the age of criminal responsibility.

Application to criminal responsibility

Because the frontal lobe is still developing during the teenage years, this research is used to argue about the age of criminal responsibility (10 in England and Wales). Students should be able to discuss both sides: the brain evidence suggests under-developed impulse control, but critics argue this does not mean young people cannot tell right from wrong.

Common mistakes

• Do not say the brain 'stops developing' at a set age like 18, development continues into the twenties.
• Do not confuse synaptic pruning (removing unused connections) with synaptogenesis (forming new connections), they are opposite processes.
• Always name Blakemore and Choudhury when discussing adolescent brain development, examiners want the specific study.
• Remember it is the frontal lobe (not the whole brain) that is linked to risk-taking and decision-making.
• Link the biology to behaviour explicitly in exam answers, do not just describe the brain in isolation.

What is social influence?

Social influence is how other people's presence, words or actions change what we think, feel or do. AQA splits this into conformity, obedience, and social change. It matters because it explains real behaviour, from peer pressure to why atrocities happen and why protest movements work.

Types of conformity

• Kelman identified three types: compliance (going along publicly but not privately agreeing, and it stops when the group isn't watching), identification (changing views to be part of a group you value, both public and private but temporary), and internalisation (genuinely changing your beliefs, both public and private, and it's permanent).
• Common mistake: students confuse identification and internalisation. Ask 'does the belief last once you leave the group?' Yes = internalisation.

Explanations for conformity

• Normative social influence (NSI): conforming to be liked or accepted, driven by a need for approval. Linked to compliance.
• Informational social influence (ISI): conforming because we believe others have better knowledge, especially in ambiguous or novel situations. Linked to internalisation.
• Common mistake: mixing these up in exam answers. NSI = fitting in emotionally; ISI = wanting to be right.

Explanations for obedience

• Agentic state: acting as an agent for someone else's wishes rather than on personal conscience, so you feel less personal responsibility.
• Legitimacy of authority: we obey people we see as having a right to direct us, such as uniformed or official figures, especially within a recognised hierarchy.
• Situational variables affecting obedience include proximity (closeness to the victim or the authority figure), location (a prestigious setting increases obedience), and uniform (a recognised uniform increases perceived legitimacy).

Resistance to social influence

• Social support: having an ally who resists makes it easier for others to resist too, weakening NSI.
• Locus of control (LOC): an internal LOC (believing outcomes are down to your own actions) is linked to greater resistance than an external LOC (believing outcomes are due to luck or other people).

Minority influence and social change

• Minority influence changes majority opinion through consistency (repeating the same message over time), commitment (showing dedication, sometimes through personal risk, called the augmentation principle), and flexibility (being willing to adapt the argument reasonably).
• The snowball effect describes how a minority view can gradually spread until it becomes the majority view, driving social change.
• Common mistake: forgetting that minority influence works slowly, through internalisation, not quick compliance.

Exam tips

• Always use the correct key term (NSI, ISI, agentic state, LOC) rather than vague description.
• Link explanations to real examples, such as obedience in a workplace or peer pressure among friends, to access application marks.

What counts as a psychological problem

AQA GCSE Psychology looks at how psychologists define, diagnose and treat mental health problems. A psychological problem is a pattern of thoughts, feelings or behaviour that causes distress or stops someone functioning normally in daily life.

Definitions of abnormality

• Deviation from social norms: behaviour that breaks unwritten social rules (this is culture and time-specific, so it can change).
• Failure to function adequately: the person cannot cope with everyday life, e.g. cannot hold down a job, maintain hygiene or relationships. Rosenhan and Seligman listed signs such as personal distress, maladaptive behaviour and unpredictability.
• Statistical infrequency: behaviour that is rare compared to the rest of the population, measured against the statistical average.
• Deviation from ideal mental health: Jahoda's checklist of qualities a mentally healthy person should have, e.g. self-esteem, coping with stress, accurate view of reality. The more criteria not met, the more abnormal.

Common mistake

Students often confuse the four definitions. Learn one clear example for each so you don't muddle deviation from social norms with statistical infrequency in the exam.

Phobias

A phobia is an irrational, excessive fear of an object or situation. Characteristics are behavioural (avoidance, panic), emotional (anxiety, unreasonable fear) and cognitive (irrational beliefs, selective attention to the threat).

Depression

Characteristics are behavioural (disruption to sleep and eating, social withdrawal), emotional (low mood, lowered self-esteem) and cognitive (poor concentration, negative self-view, absolutist 'black-and-white' thinking).

OCD (obsessive-compulsive disorder)

Characteristics are behavioural (compulsions, avoidance), emotional (anxiety, distress, guilt) and cognitive (obsessive thoughts, awareness that thoughts are irrational).

Explanations and treatments

• The behaviourist approach explains phobias through classical conditioning (association) and treats them with systematic desensitisation (gradual exposure paired with relaxation, working up a fear hierarchy) or flooding (immediate, intense exposure).
• The cognitive approach explains depression through Beck's negative triad (negative views of self, world and future) and Ellis's ABC model (Activating event, Belief, Consequence), treated with CBT that challenges irrational beliefs.

Exam tip

Always link the treatment back to its explanation: behaviourist treatments (desensitisation, flooding) match behaviourist explanations (conditioning); cognitive treatments (CBT) match cognitive explanations (irrational thinking). Mixing these up is the most common lost mark.

Why research methods matter

Psychology is a science, so it needs a reliable way to test ideas. Research methods is about how psychologists collect and check data, and it's tested through both recall questions and 'evaluate this study' style questions.

Types of study

• Experiments (lab, field, natural) test cause and effect by changing an independent variable (IV) and measuring a dependent variable (DV).
• Lab experiments happen in controlled settings, giving high control but can feel artificial.
• Field experiments happen in real-life settings, more natural but harder to control variables.
• Natural experiments use a naturally occurring IV (like a disaster or policy change) that the researcher cannot manipulate.
• Correlations measure the relationship between two co-variables without manipulating anything, so they cannot show cause and effect, only that variables are linked.

Sampling methods

• Random sampling: every person has an equal chance of being picked, often using random number generators.
• Opportunity sampling: using whoever is available and willing at the time; quick but biased.
• Volunteer sampling: participants self-select, often by responding to an advert; can attract a certain type of person.
• Systematic sampling: picking every nth person from a list.

Key terms to know exactly

• Aim: a general statement of what the study intends to investigate.
• Hypothesis: a precise, testable prediction, either directional (states the direction of the difference/effect) or non-directional (predicts a difference but not the direction).
• Extraneous variable: any variable other than the IV that could affect the DV if not controlled.
• Confounding variable: an extraneous variable that has actually varied systematically with the IV, making results hard to interpret.
• Demand characteristics: cues that make participants guess the aim and change their behaviour.
• Investigator effects: ways the researcher unconsciously influences the results.

Ethics (BPS guidelines)

• Informed consent must be gained wherever possible.
• Right to withdraw at any point, without penalty.
• Protection from harm, both physical and psychological.
• Confidentiality of personal data.
• Deception should be avoided unless justified, and must be followed by debriefing.

Data and analysis

• Quantitative data is numerical (counts, scores); qualitative data is descriptive (words, opinions).
• Measures of central tendency: mean (average, affected by outliers), median (middle value, better with outliers), mode (most common value).
• Common mistakes: confusing correlation with causation, muddling reliability (consistency) with validity (measuring what it claims to), and forgetting that a directional hypothesis is used when past research suggests a specific outcome.