Social influence: conformity

Conformity means changing behaviour or beliefs because of real or imagined group pressure.

Asch (1951) found genuine participants agreed with an obviously wrong majority on line-length judgements on 36.8% of trials, and 75% conformed at least once.

Deutsch and Gerrard split this into two explanations.

• Normative Social Influence (NSI): conforming to be liked or avoid rejection, an emotional route.
• Informational Social Influence (ISI): conforming because we believe others have better knowledge, more likely when a task is ambiguous or we lack expertise.

Group size, unanimity and task difficulty all affect conformity rates. A single dissenter sharply cuts conformity, even if that dissenter is also wrong, because it breaks unanimity.

Obedience

Milgram (1963) found 65% of participants delivered the full 450 volts when ordered by an authority figure, even though most showed real distress.

Situational variables that reduced obedience: distance from the victim, proximity to the authority figure being reduced, location moving away from a prestigious institution, and a disobedient peer modelling refusal.

Explanations include the agentic state (seeing oneself as an agent carrying out another's wishes, removing personal responsibility) and legitimacy of authority (obedience rises when the authority is seen as socially sanctioned).

Resistance to social influence

Social support (having an ally who resists) and having an internal locus of control (believing outcomes are down to your own actions, not luck or others) both increase the ability to resist conformity and obedience.

Memory

The multi-store model (Atkinson and Shiffrin) proposes three separate stores.

• Sensory register: huge capacity, held for under half a second.
• Short-term memory (STM): capacity 7±2 items (Miller), duration about 18-30 seconds without rehearsal, encoded mainly acoustically.
• Long-term memory (LTM): potentially unlimited capacity and duration, encoded mainly semantically.

Rehearsal transfers information from STM to LTM; this is a common exam point examiners reward.

Common mistakes

• Confusing NSI and ISI, or forgetting NSI is emotional/social and ISI is about wanting to be right.
• Writing 'Milgram proved people are evil' rather than emphasising the situational explanations his study supports.
• Quoting STM duration and capacity the wrong way round; capacity is items, duration is seconds.
• Forgetting that resistance factors (social support, locus of control) apply to BOTH conformity and obedience essays.

Attachment: the key studies

Attachment is the emotional bond between infant and caregiver. Edexcel focuses on how early attachment links to later mental health (psychopathology).

• Bowlby's Maternal Deprivation Hypothesis: continuous care from one primary attachment figure is needed in a critical period (first 2.5 years, extending to age 5). Deprivation in this window causes long-term harm.
• Bowlby's 44 Thieves Study (1944): 44 juvenile thieves compared to 44 non-thief controls. 32% of thieves showed 'affectionless psychopathy' linked to early separation from mother, versus 0% of controls.
• Affectionless psychopathy: lack of guilt or empathy, an inability to form close relationships, often linked to delinquency and antisocial behaviour.

The Robertsons and institutionalisation

• James Robertson filmed children in hospital/residential care separated from parents, showing distress in stages: protest, despair, detachment (PDD).
• Romanian orphan studies (Rutter's ERA study) show institutionalisation before 6 months can usually be recovered from with good later care; after 6 months, disinhibited attachment and cognitive delay are more likely to persist.

Attachment style and later disorders

• Insecure attachment (avoidant or resistant/ambivalent) in infancy is associated with higher risk of anxiety disorders, depression and conduct problems in later life.
• Disorganised attachment (often linked to abuse or neglect) carries the highest risk of later psychopathology, including borderline personality traits.
• Internal Working Model: the infant's first relationship becomes a template for all future relationships; a damaged template increases vulnerability to psychological disorder.

Evaluation points (always needed for AO3 marks)

• Correlation, not causation: many 'affectionless psychopaths' had multiple risk factors (poverty, family conflict), not just separation, so Bowlby's claims are criticised as too deterministic.
• Retrospective and self-report data (as used by Bowlby) is open to bias.
• Real-world application is strong: influenced hospital visiting policy, adoption practice and childcare guidance.

Common mistakes

• Confusing 'deprivation' (loss of an attachment already formed) with 'privation' (never forming one at all) — privation tends to have worse outcomes.
• Writing 'critical period' when Edexcel spec language now often prefers 'sensitive period' for later stages — know both terms and use them correctly in context.
• Forgetting to use named studies (Bowlby 1944, Robertson, Rutter/ERA) as concrete AO2 evidence rather than vague description.

Approaches: the basics

Psychology has several competing approaches, each with its own assumptions about behaviour.

• Behaviourist: only study observable behaviour; learning happens through conditioning.
• Classical conditioning (Pavlov): learning by association - a neutral stimulus (NS) paired repeatedly with an unconditioned stimulus (UCS) becomes a conditioned stimulus (CS) producing a conditioned response (CR).
• Operant conditioning (Skinner): learning through consequences. Positive reinforcement adds a pleasant outcome; negative reinforcement removes an unpleasant one; punishment decreases behaviour.
• Social learning theory (Bandura): learning through observation and imitation of a role model, mediated by attention, retention, motor reproduction and motivation. Vicarious reinforcement matters - seeing someone else rewarded increases the chance of imitation.

Cognitive and biological approaches

• Cognitive approach: the mind works like an information processor (input, processing, output); uses schemas (mental frameworks built from experience) and models memory/thinking through inference from behaviour since mental processes cannot be observed directly.
• Biological approach: behaviour explained through genes, neurochemistry and brain structure. Twin studies compare concordance rates between monozygotic (MZ, share 100% DNA) and dizygotic (DZ, share about 50% DNA) twins to work out heritability.

Biopsychology: the nervous system

• The nervous system splits into the Central Nervous System (CNS: brain and spinal cord) and Peripheral Nervous System (PNS).
• PNS splits into the somatic (voluntary, sensory/motor) and autonomic (involuntary) nervous systems.
• Autonomic splits into sympathetic (fight or flight - increases heart rate, dilates pupils) and parasympathetic (rest and digest - opposite effects).

Neurons and synaptic transmission

• Three neuron types: sensory (receptor to CNS), relay (connects neurons within CNS), motor (CNS to effector).
• A neuron has dendrites, a cell body (soma), an axon (often myelinated for faster transmission via saltatory conduction) and terminal buttons.
• At the synapse, an electrical impulse triggers release of neurotransmitters (e.g. serotonin, dopamine) from vesicles across the synaptic gap, binding to receptors on the postsynaptic membrane, either exciting (depolarising, increasing likelihood of firing) or inhibiting (hyperpolarising) the next neuron.
• Summation: the neuron only fires if the combined excitatory and inhibitory signals reach the threshold.

Common mistakes

• Do not confuse classical (association, before behaviour) with operant (consequence, after behaviour) conditioning.
• Learn approaches as separate but comparable - always be ready to compare two approaches (e.g. cognitive vs biological) on determinism, reductionism, nature/nurture and usefulness.
• Sympathetic vs parasympathetic is a very common mix-up - sympathetic speeds things up, parasympathetic calms things down.
• Remember neurotransmitters are chemical, not electrical - the impulse becomes chemical only at the synapse.

What research methods covers

This topic is the toolkit examiners test hardest: how psychologists design, run and evaluate studies. You need to know each method's strengths and weaknesses, plus how to apply stats and ethics to unfamiliar scenarios.

Experimental methods

• Laboratory experiment: high control, IV manipulated by researcher, low ecological validity.
• Field experiment: IV manipulated in a natural setting, better ecological validity, less control.
• Natural experiment: IV occurs naturally (not manipulated), used when it would be unethical or impossible to manipulate; cannot establish causation as confidently.
• Quasi-experiment: IV is a pre-existing difference (e.g. age, gender) so participants cannot be randomly allocated.

Design and sampling

• Experimental designs: independent groups, repeated measures, matched pairs. Repeated measures controls participant variables but risks order effects (counterbalance using ABBA to fix this).
• Sampling methods: random, systematic, stratified, opportunity, volunteer. Random sampling gives every member an equal chance but is time-consuming; opportunity sampling is quick but biased.
• Aim: a general statement of purpose. Hypothesis: a testable, precise prediction. Directional (one-tailed) hypotheses predict the direction of a difference; non-directional (two-tailed) just predict a difference exists.

Validity and reliability

• Internal validity: whether the study measured what it claimed to (watch for confounding/extraneous variables, demand characteristics, investigator effects).
• External validity: ecological validity, population validity, temporal validity.
• Reliability: consistency of a measure. Test-retest reliability checks the same test over time; inter-observer reliability checks agreement between two observers, usually reported as a correlation coefficient (aim for 0.8 or above).

Data and stats

• Quantitative data: numerical, easy to analyse statistically. Qualitative data: descriptive, rich detail but harder to compare.
• Levels of measurement: nominal (categories), ordinal (ranked, no equal intervals), interval/ratio (equal intervals, true zero for ratio).
• Measures of central tendency: mean (affected by outliers), median (middle value, good for skewed data), mode (most frequent, best for nominal data).
• Measures of dispersion: range (quick but distorted by extreme scores) and standard deviation (more precise, shows spread around the mean).
• Statistical significance in psychology is conventionally set at p ≤ 0.05 (a 5% probability the result is due to chance).

Common mistakes to avoid

• Confusing reliability (consistency) with validity (accuracy/truth) — they are not the same thing.
• Forgetting that correlations show a relationship, not causation.
• Writing a hypothesis that isn't testable or operationalised.
• Mixing up independent groups and repeated measures when identifying a design from a scenario.

Ethics

• BPS guidelines require informed consent, right to withdraw, confidentiality, protection from harm, and debriefing. Deception must be justified and addressed fully at debrief.

What issues and debates actually cover

This topic is synoptic, meaning it gets applied across every other unit (biopsychology, clinical, criminal, cognitive, social). Edexcel expects you to evaluate studies and theories using these lenses, not just describe them.

Gender and culture bias

• Alpha bias exaggerates differences between genders or cultures (eg early evolutionary explanations of infidelity).
• Beta bias ignores or minimises differences, often by generalising male-only or Western-only findings to everyone.
• Androcentrism means male behaviour is treated as the norm, making female behaviour look abnormal by comparison.
• Ethnocentrism judges other cultures using your own culture's standards, seen in early intelligence testing.
• Imposed etic is applying a theory developed in one culture (usually Western) to another culture as if it were universal, eg Ainsworth's Strange Situation being used worldwide despite being built on US infant norms.

Free will versus determinism

• Hard determinism says all behaviour is caused by internal or external forces, leaving no genuine choice.
• Soft determinism, favoured by most psychologists, allows some conscious choice within the constraints of causal factors.
• Biological determinism points to genes, hormones and brain structure (eg the COMT and MAOA gene links to aggression).
• Environmental determinism points to conditioning history (Skinner's behaviourism).
• The scientific emphasis on causal laws makes psychology naturally deterministic, which conflicts with the legal system's assumption of free will and moral responsibility.

Reductionism versus holism

• Biological reductionism explains behaviour purely at the level of neurons, hormones or genes.
• Environmental reductionism (stimulus-response) breaks behaviour into simple learned associations.
• Holism argues behaviour must be studied as a whole system, since interactions between components produce effects that cannot be predicted from the parts alone, eg social identity effects in groups.

Nature-nurture and diathesis-stress

• The diathesis-stress model is the key exam example: a genetic vulnerability (diathesis) only leads to disorder if triggered by an environmental stressor.
• Modern gene-environment interaction models (eg epigenetics) have replaced simple nature vs nurture arguments.

Idiographic versus nomothetic

• Idiographic approaches (case studies, humanistic) focus on the unique individual.
• Nomothetic approaches (biological, behaviourist) aim to establish general laws through large samples and statistics.

Ethical implications of research

• Beyond the BPS Code of Ethics protecting participants, this concerns the wider impact of publishing findings on public policy, groups in society, and how findings might be misused.

Common mistakes

• Confusing alpha bias with androcentrism; they overlap but are not identical.
• Writing generic 'this is deterministic' points without naming the type of determinism.
• Forgetting to apply issues and debates to named studies from other topics when the question asks for application marks.

Relationships

Edexcel covers attraction and maintenance theories.

• Filter theory (Kerckhoff and Davis): three filters narrow the field of eligibles over time - social demography (proximity, class, faith), similarity in attitudes, then complementarity of needs. Early relationships filtered by demography, later by deeper compatibility.
• Social exchange theory (Thibaut and Kelley): relationships judged on rewards minus costs, compared against a comparison level (CL) and a comparison level for alternatives (CLalt). If CLalt looks better, a partner may leave even a 'profitable' relationship.
• Equity theory (Walster): satisfaction depends on the RATIO of inputs to outputs matching between partners, not equal amounts - both over-benefiting and under-benefiting cause distress.
• Rusbult's investment model: commitment predicted by satisfaction, low quality of alternatives, and size of investment (time, effort, shared possessions).

Schizophrenia

• Diagnosis uses DSM-5 (US) or ICD-11 (WHO) - Edexcel expects awareness that at least ONE month of active positive symptoms is typically required for a DSM-5 diagnosis, alongside 6 months of disturbance overall.
• Positive symptoms: hallucinations, delusions, disorganised speech. Negative symptoms: avolition, alogia, flat affect.
• Biological explanations: dopamine hypothesis (excess dopamine activity, especially in the mesolimbic pathway) and genetic factors (concordance rates higher in MZ twins than DZ twins, e.g. Gottesman's family studies).
• Psychological explanations: family dysfunction (e.g. expressed emotion - high EE households linked to relapse) and cognitive explanations (dysfunctional thought processing).
• Treatments: typical antipsychotics (dopamine antagonists, e.g. chlorpromazine) block D2 receptors; atypical antipsychotics (e.g. clozapine) act on dopamine and serotonin with fewer motor side effects. CBT and family therapy are key psychological treatments.
• Common mistake: don't say schizophrenia means 'split personality' - that is a myth; it is a disorder of disrupted thought and perception.

Aggression

• Biological explanations: the limbic system (especially the amygdala) and neurotransmitters (low serotonin linked to reduced impulse control, high testosterone linked to aggression).
• Genetic factors: the MAOA gene ('warrior gene') low-activity variant linked to aggressive behaviour, especially with childhood maltreatment (gene-environment interaction).
• Social learning theory (Bandura): aggression learned through observation and imitation of role models, strengthened by vicarious reinforcement - link to the Bobo doll studies.
• De-individuation theory: reduced self-awareness and accountability in crowds/anonymity increases aggressive behaviour.
• Institutional aggression: explanations include the importation model (inmates bring pre-existing traits in) versus the deprivation model (aggression is a response to prison conditions).

Common exam mistakes across this option

• Always name the specific study/theorist, not just 'a study showed...'.
• Distinguish description (AO1) from evaluation (AO3) - examiners want explicit evaluation words like 'a strength/limitation of this is...'.
• Learn exact terms: comparison level, expressed emotion, mesolimbic pathway, MAOA gene - vague paraphrasing loses marks.