THE BRAIN & CONSCIOUSNESS
Why do we dream? What happens in our brain during sleep? Discover REM sleep, lucid dreaming, and what dreams really mean!
Your brain's shortcuts lead to systematic errors in thinking. Discover the biases that shape every decision you make — and how to outsmart your own mind.
What makes you "you"? Explore personality types, ego, the unconscious mind, and how identity forms through childhood, culture, and experience.
What IS consciousness? Why does subjective experience exist at all? The "hard problem" of consciousness is one of the deepest unsolved questions in science — where neuroscience meets philosophy.
Memory is not a recording — it's a reconstruction. Every time you remember something, you slightly change it. False memories, the forgetting curve, and why eyewitness testimony is unreliable.
You cannot truly multitask — your brain just switches between tasks rapidly. Attention is a finite resource. Learn what focus really is, why smartphones shatter it, and how to reclaim it.
EMOTIONS & MOTIVATION
Where do emotions come from? Fear hijacks your brain in a fraction of a second. Joy floods you with dopamine. Emotions evolved to keep you alive — and understanding them gives you power over them.
Fear is your oldest survival system. In a real emergency it saves your life. But when the brain's alarm system fires for emails and social media, anxiety is the result. Here's what's happening — and how to calm it.
Research consistently shows that after a certain income level, more money doesn't make us happier. Relationships, meaning, and autonomy matter more. The science of wellbeing has surprising conclusions.
Paying people for creative work often makes them worse at it. Intrinsic motivation — doing something because it's meaningful — is more powerful and durable than rewards. Why? And how do you cultivate it?
Short-term stress sharpens performance. Chronic stress wears your body down over time. Cortisol, the HPA axis, and how to build resilience when pressure never switches off.
Addiction isn't a moral failure — it's a hijacking of the brain's dopamine reward system. From drugs and alcohol to social media and gambling, the same neural pathways are involved.
SOCIAL PSYCHOLOGY
We are fundamentally social creatures. The presence of others changes how we behave, think, and perform. Social facilitation, the bystander effect, and why humans need belonging to survive.
Asch showed people would deny the evidence of their own eyes to fit in. Milgram showed 65% of participants went to the maximum shock level when an authority figure told them to continue. What does this say about us?
Reciprocity, scarcity, authority, social proof, liking, commitment — Robert Cialdini identified six universal principles of persuasion that advertisers, politicians, and salespeople use on you every day.
In groups, intelligent people make terrible decisions. Groupthink silences dissent. Tribalism makes us dehumanise outsiders. Understanding group psychology is essential to understanding history.
Stereotypes are cognitive shortcuts — the brain categorising quickly to save energy. Implicit bias affects even people who believe they're unbiased. Understanding the psychology of prejudice is the first step to reducing it.
DEVELOPMENT & LEARNING
Jean Piaget mapped how children's thinking develops through four stages. Babies have no concept of object permanence. Toddlers can't take another's perspective. By adolescence, abstract reasoning emerges.
John Bowlby showed that the bond between infant and caregiver shapes emotional development, relationship patterns, and mental health for life. Secure, anxious, avoidant — which attachment style are you?
Pavlov's dogs salivated at a bell. Skinner's rats pressed levers for food. Classical and operant conditioning explain how all animals — including humans — learn, form habits, and can be trained.
IQ tests measure some aspects of intelligence — but not creativity, emotional intelligence, or wisdom. Howard Gardner proposed 8 types of intelligence. Is genius born or made? The evidence is nuanced.
Does language shape how we think? The Sapir-Whorf hypothesis asks whether words guide our minds, or our minds guide our words. Whorf once claimed Hopi speakers experience time differently — later linguists showed the story is more complex.
MENTAL HEALTH
About 1 in 4 people face a mental health challenge at some point in life. Understanding the spectrum from normal stress to clinical disorder, what causes mental illness, and why asking for help is strength, not weakness.
Research links PTSD to changes in brain areas like the amygdala and hippocampus in some studies. PTSD is not weakness; it's an injury. Understanding it is the first step to healing.
Cognitive Behavioural Therapy works by identifying and challenging distorted thought patterns. Brain scans show therapy literally rewires neural pathways — producing changes as measurable as medication.
MRI studies show 8 weeks of mindfulness practice physically thickens the prefrontal cortex and shrinks the amygdala. Ancient Buddhist techniques are now backed by neuroscience — and prescribed by doctors.
The Big Five personality traits — Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism — are the most scientifically validated model of personality. Are you born with your personality, or do you choose it?
FAMOUS EXPERIMENTS
In 1961, Stanley Milgram found 65% of ordinary Americans would administer apparently lethal electric shocks to a stranger — simply because a man in a lab coat told them to. The most disturbing experiment in psychology.
In 1971, Philip Zimbardo assigned students as guards or prisoners in a fake jail. Within days, guards became brutal and prisoners became traumatised. It had to be stopped after 6 days. What does this mean about human nature?
Ivan Pavlov rang a bell before feeding his dogs until the bell alone made them salivate. Classical conditioning is everywhere — from phobias to advertising to your morning coffee routine.
Abraham Maslow proposed that human needs are arranged in a pyramid — survival first, then safety, belonging, esteem, and finally self-actualisation. Is it right? And what does it tell us about what humans truly want?
In the 1970s, Walter Mischel offered children one marshmallow now or two if they waited 15 minutes. Children who waited grew up to have better grades, health, and earnings. But the story is more complicated than it seems.
FAMOUS PSYCHOLOGISTS & IDEAS
Freud argued that most of the mind is unconscious — a seething reservoir of repressed desires, fears, and memories that shapes behaviour without our awareness. Much of his theory is wrong. Much of his insight endures.
Jung proposed a collective unconscious shared by all humans — a deep layer of psyche containing universal archetypes like the Hero, the Shadow, and the Self. His ideas spawned the Myers-Briggs personality test.
Proximity, similarity, reciprocity — the factors that determine who we fall in love with are more predictable than romance suggests. Sternberg's triangle of love: intimacy, passion, and commitment.
Identical twins raised apart are remarkably similar. But environment shapes gene expression. The nature vs nurture debate has been replaced by a more nuanced question: how do genes and environment interact?
Daniel Goleman argued that emotional intelligence — self-awareness, empathy, and social skills — predicts life success better than IQ. Mirror neurons may be the biological basis of empathy.
Carol Dweck found that students who believe intelligence is fixed give up when they fail. Students who believe it's growable through effort keep trying — and perform dramatically better. The belief itself changes the outcome.
Hannah Arendt called it "the banality of evil" — the Holocaust was carried out mostly by ordinary people following orders. Psychology explains how ordinary humans commit atrocities — and what we can do to prevent it.
fMRI scans, AI pattern recognition, and psychedelic-assisted therapy are transforming psychology. We're closer than ever to understanding consciousness — and to treating the mental health crisis reshaping modern society.
BIOLOGICAL PSYCHOLOGY
Neurons communicate via electrical impulses (action potentials) and chemical signals (neurotransmitters). Axons carry the signal; dendrites receive it. At the synapse, neurotransmitters cross the gap and bind to receptors.
The brain's four lobes each specialise: frontal (decision-making, personality, language production), parietal (sensory integration, spatial awareness), temporal (hearing, memory, language comprehension), occipital (vision).
Dopamine: reward, motivation, movement. Serotonin: mood, sleep, appetite. Noradrenaline: arousal, attention, fight-or-flight. GABA: inhibition (too little = anxiety). Glutamate: excitation (too much = neurotoxicity). Acetylcholine: muscle contraction, learning, memory.
The left hemisphere controls the right side of the body; right controls left. Sperry and Gazzaniga's split-brain research (severing the corpus callosum to treat epilepsy) revealed that the two hemispheres have specialised...
The endocrine system — glands releasing hormones into the bloodstream — regulates slow, sustained responses versus the nervous system's fast electrical signals.
Testosterone correlates with aggression, competitive behaviour, risk-taking, and dominance. Cortisol rises with stress, impairs hippocampal memory, and can cause anxiety disorders with chronic elevation.
Twin studies separate genetic from environmental influences: identical twins (100% shared genes) vs fraternal twins (50%). Heritability of IQ: ~50% in childhood, ~80% in adulthood. Heritability of schizophrenia: ~80%.
Evolutionary psychology applies natural selection to psychological traits: mate preferences evolved to maximise reproductive success, fear responses to avoid ancestral dangers, in-group favouritism to benefit genetic relatives.
Walter Cannon's fight-or-flight: stress activates the sympathetic nervous system (heart rate, adrenaline, dilated pupils, diverted blood flow to muscles). Modern addition: freeze response (parasympathetic dorsal vagal activation).
The suprachiasmatic nucleus (SCN) in the hypothalamus is the body's master clock, entrained by light via retinal ganglion cells. Sleep architecture: NREM (stage 1-3) and REM cycling every ~90 minutes.
Early brain development involves massive synaptogenesis followed by synaptic pruning — use-dependent selection of circuits. Adult neuroplasticity: hippocampal neurogenesis continues throughout life (enhanced by exercise, impaired by chronic stress).
Selye's General Adaptation Syndrome: alarm (HPA activation) → resistance (adaptation) → exhaustion (physiological depletion). Psychological stress appraisal (Lazarus):
Broca's area (left frontal): speech production. Wernicke's area (left temporal): language comprehension. Motor cortex (primary): voluntary movement, somatotopic map (homunculus). Visual cortex (occipital): feature detection, V1-V5 hierarchy.
Agonists increase neurotransmitter activity; antagonists block it. SSRI antidepressants inhibit serotonin reuptake (increasing synaptic serotonin). Benzodiazepines enhance GABA (reducing anxiety). Antipsychotics block dopamine D2 receptors. Stimulants increase dopamine and noradrenaline.
Psychoneuroimmunology examines how stress, emotions, and social factors affect immune function. Chronic stress elevates cortisol, suppressing immune responses — explaining why stressed people get more colds.
Gate Control Theory (Melzack and Wall): pain signals can be modulated at the spinal cord by cognitive and emotional inputs — explaining why distraction, hypnosis, and placebos reduce pain.
Addiction hijacks the dopaminergic reward system. Repeated substance use → tolerance (less dopamine response) → withdrawal (negative affect when absent) → craving (conditioned cue-triggered dopamine spike).
The amygdala processes emotional significance, mediates fear conditioning, and triggers rapid threat responses before cortical processing happens — the 'low road' (LeDoux). Amygdala hyperactivity characterises anxiety disorders and PTSD.
Biological sex differences in the brain are real but small and overlapping — not categorical. Average differences exist in the amygdala, hippocampus, and certain cortical regions.
fMRI measures blood oxygen level-dependent (BOLD) signal as a proxy for neural activity. EEG measures electrical activity with millisecond temporal resolution but poor spatial resolution.
COGNITIVE PSYCHOLOGY
Atkinson-Shiffrin Multi-Store Model: sensory → short-term → long-term memory, each with distinct capacity and duration. Baddeley's Working Memory Model replaced STM with separate phonological loop, visuospatial sketchpad, and central executive.
Levels of processing (Craik and Lockhart): deeper semantic processing produces stronger memory traces than shallow structural processing. Context-dependent memory: recall better in the same environment as encoding.
Decay theory: memories fade without use. Interference theory: retroactive (new learning disrupts old) and proactive (old learning disrupts new) interference.
Loftus and Palmer's car crash study: 'smashed' vs 'contacted' leads to higher speed estimates and false memories of broken glass. The misinformation effect shows post-event information integrates into memories seamlessly.
Cherry's cocktail party effect: selective attention to one conversation while filtering others. Broadbent's filter model: early selection before semantic processing. Treisman's attenuation model: unattended channel reduced but not eliminated.
Perception is active construction, not passive reception. Gestalt principles (proximity, similarity, closure) show the brain imposes structure. Bottom-up processing: data-driven. Top-down processing: concept-driven.
Template matching vs prototype models vs feature analysis. Geon theory (Biederman): objects recognised by geometric primitives.
Problem solving: algorithms (systematic search) vs heuristics (shortcuts — fast but error-prone). Functional fixedness: difficulty using objects in new ways.
Framing effect: choices depend on how options are presented ('save 200 lives' vs '400 die'). Availability heuristic: judging probability by ease of recall (plane crashes vs car crashes).
Sapir and Whorf proposed language determines thought (strong Whorfian) or influences it (weak). Evidence for weak Whorfianism:
Schemas are cognitive frameworks organising knowledge and guiding attention and interpretation. They cause reconstructive errors (Bartlett's 'War of the Ghosts': British students recalled the Native American story in culturally familiar terms).
Spearman's g (general intelligence). Gardner's multiple intelligences: linguistic, logical, spatial, musical, kinaesthetic, interpersonal, intrapersonal, naturalist (influential but empirically contested). Sternberg's triarchic theory: analytical, creative, practical.
Metacognition — awareness and regulation of one's own cognitive processes — predicts academic achievement beyond IQ. Calibration: knowing what you know and don't know.
Kahneman's System 1 and System 2: fast-automatic-intuitive vs slow-deliberate-analytical processing. System 1 uses heuristics efficiently but produces systematic errors. System 2 is accurate but effortful and rarely engaged.
Working memory has limited capacity (7±2 chunks, Miller). Cognitive load = intrinsic (content complexity) + extraneous (poor instruction design) + germane (schema formation effort).
Priming: exposure to a stimulus influences responses to a subsequent related stimulus — often without awareness. Implicit Association Test (IAT) measures unconscious associations (race, gender, weight).
Chase and Simon's chess expertise: grandmasters recognise ~50,000 patterns (chunks), not plan more deeply. Ericsson's deliberate practice: 10,000 hours of focused, feedback-rich practice builds expertise through progressive challenging of comfort zone.
Brain lesions, strokes, and TBIs create natural experiments. Phineas Gage: iron rod destroyed frontal cortex → personality changed (emotional regulation lost).
Salovey and Mayer's model: perceiving emotions, using emotions to facilitate thought, understanding emotions, and managing emotions. Goleman's popular version added motivation and social skills.
AI systems now outperform humans on many cognitive tasks: chess (1997), Go (2016), protein folding (2020), certain image recognition. But AI lacks common sense, context, and embodied understanding.
ABNORMAL PSYCHOLOGY & MENTAL HEALTH
DSM-5 (American Psychiatric Association) and ICD-11 (WHO) classify mental disorders by clusters of symptoms, duration, and impairment. Categorical vs dimensional diagnosis debate: most disorders exist on continua, not as discrete categories.
Major Depressive Disorder: persistent low mood, anhedonia, fatigue, worthlessness, concentration difficulties, sleep disturbance. Biological models: monoamine hypothesis (low serotonin/noradrenaline). Cognitive model (Beck): negative triad of self, world, future.
GAD (generalised worry), panic disorder (unexpected attacks), specific phobias (object/situation fears), social anxiety disorder, agoraphobia. Common mechanism: hyperactive threat appraisal and avoidance behaviour that prevents extinction of fear.
Positive symptoms (added to normal function): hallucinations, delusions, disorganised speech. Negative symptoms (reduced function): flat affect, poverty of speech, social withdrawal. Dopamine hypothesis: excess dopamine activity in mesolimbic pathway.
OCD: intrusive thoughts (obsessions) → anxiety → compulsive rituals to reduce anxiety → temporary relief reinforces compulsions.
PTSD: re-experiencing (flashbacks, nightmares), avoidance, negative cognitions/mood, hyperarousal — following exposure to life-threatening trauma. Biological: chronic HPA dysregulation, amygdala hyperactivity, hippocampal volume reduction (cause or consequence?).
Bipolar I: full manic episodes (elevated mood, decreased sleep need, grandiosity, impulsivity, psychosis) alternating with depressive episodes or mixed states. Bipolar II: hypomania (less severe) + depression. Cyclothymia: milder chronic cycling.
Anorexia nervosa: restriction leading to dangerously low weight, intense fear of gaining weight, distorted body image. Highest mortality of any mental disorder. Bulimia nervosa: binge-purge cycles without low weight.
DSM-5 clusters: Cluster A (odd/eccentric: schizotypal, paranoid, schizoid), Cluster B (dramatic/emotional: borderline, antisocial, histrionic, narcissistic), Cluster C (anxious/fearful: avoidant, dependent, OCPD). BPD (borderline): emotional dysregulation, fear of abandonment, unstable identity, self-harm.
ASD: persistent differences in social communication and restricted, repetitive behaviours. Now understood as a spectrum with huge heterogeneity. Monotropism model: intense focus on specific interests.
ADHD: inattention and/or hyperactivity-impulsivity that impairs function across settings. Three presentations: predominantly inattentive, hyperactive/impulsive, combined. Neurobiological: prefrontal dopamine-noradrenaline dysregulation impairing executive function. Methylphenidate (Ritalin) and amphetamine salts are effective.
Aaron Beck developed CBT (Cognitive Behavioural Therapy) through systematic observation that depressed patients had automatic negative thoughts clustered in three domains:
Classical conditioning: Wolpe's systematic desensitisation — pair feared stimulus with relaxation at increasing proximity. Exposure therapy: exposure without safety behaviours → anxiety → spontaneous extinction.
Freud's unconscious conflict model: unresolved early conflicts expressed via defence mechanisms (repression, projection, displacement). Free association, dream analysis, and transference interpretation reveal unconscious material.
Carl Rogers' person-centred therapy: unconditional positive regard, empathy, and congruence create conditions for self-actualisation. Client knows their own needs better than the therapist.
MBSR (Mindfulness-Based Stress Reduction, Kabat-Zinn) and MBCT (Mindfulness-Based Cognitive Therapy) train non-judgmental attention to present-moment experience. MRI shows structural changes in prefrontal cortex and amygdala with 8 weeks of practice.
Developmental disorders (ASD, ADHD, dyslexia, DLD) emerge in childhood. Reactive attachment disorder: severely disrupted early attachment → pervasive relational difficulties. Conduct disorder: persistent rule-breaking → callous-unemotional traits predict later antisocial personality.
Link et al's modified labelling theory: the label 'mentally ill' triggers stereotype awareness → anticipated rejection → social withdrawal → self-stigma → worse outcomes.
Medical model: mental disorder = disease with biological cause, diagnosed, and treated medically. Engel's biopsychosocial model: mental disorders have biological (genes, neurotransmitters), psychological (cognitions, attachment), and social (poverty, trauma, discrimination) causes...
Hearing voices (auditory hallucinations) is more common than assumed — 5-13% of the population at some time, mostly without distress. Hearing Voices Network: voices as meaningful experiences rather than pathological symptoms.
SOCIAL & DEVELOPMENTAL PSYCHOLOGY (ADVANCED)
Tajfel and Turner: people define their self-concept partly through group membership (social identity). Even minimal groups (random assignment) trigger in-group favouritism. Social comparison and intergroup differentiation maintain positive social identity.
Fundamental Attribution Error: overattributing others' behaviour to disposition (character) and underattributing to situation. Actor-observer bias: I attribute my failures to situation, yours to your character.
Festinger (1957): holding contradictory beliefs or behaving against beliefs creates dissonance — an unpleasant state motivating attitude change. Post-decisional dissonance: after a choice, its negatives fade and its positives amplify.
Explicit prejudice (conscious, controllable) vs implicit prejudice (automatic, measured by IAT). Realistic conflict theory (Sherif's Robbers Cave): competition for scarce resources creates intergroup conflict, reversed by superordinate goals.
Elaboration Likelihood Model (Petty and Cacioppo): central route (systematic argument processing) vs peripheral route (heuristics: source attractiveness, consensus). Fear appeals: effective when combined with high efficacy (belief you can act).
Biological: testosterone, serotonin, amygdala volume. Frustration-aggression hypothesis (Dollard): blocked goals frustrate → aggression. Social learning (Bandura's Bobo doll): aggression learned through observation. General Aggression Model (Anderson): cognitive, affective, and arousal pathways.
Biological: sex chromosomes → gonads → hormones → differentiating brain and body. Psychoanalytic: gender identity through identification with same-sex parent. Social learning: gender-typed behaviour learned through reinforcement and modelling.
Bowlby's attachment extends throughout life: Adults form attachment bonds with romantic partners. Hazan and Shaver classified adult attachment into secure, anxious-preoccupied, dismissing-avoidant, and fearful-avoidant styles.
Bystander effect (Darley and Latané): likelihood of helping decreases with number of bystanders (diffusion of responsibility, pluralistic ignorance). Empathy-altruism hypothesis (Batson): genuine empathic concern motivates altruistic helping.
Piaget: heteronomous (rules absolute, consequences matter) → autonomous (intentions matter, rules are social agreements). Kohlberg's stages: pre-conventional (reward/punishment), conventional (social norms), post-conventional (universal principles).
Prefrontal cortex (PFC) matures last — adolescents often show heightened sensation-seeking (limbic system, fully developed) without equivalent impulse control (PFC, still developing).
Piaget: children progress through stages — sensorimotor (0-2, object permanence), pre-operational (2-7, egocentrism, symbolic thought, conservation failures), concrete operational (7-11, conservation mastered), formal operational (12+, abstract hypothetical thinking).
Vygotsky: cognitive development occurs in social interaction before internalisation. Zone of Proximal Development (ZPD): the gap between what a child can do alone and with guidance
Erikson's psychosocial stages span the whole lifespan: trust vs mistrust (infancy), autonomy vs shame (toddler), initiative vs guilt (preschool), industry vs inferiority (school age), identity vs role confusion (adolescent), intimacy vs isolation...
William James: the 'I' (observer) and the 'Me' (observed). Rogers: the self-concept (how I actually am) vs ideal self (how I want to be)
Triandis: individualism (self as independent, personal goals primary) vs collectivism (self as interdependent, group goals primary). East Asian collectivist cultures show smaller fundamental attribution error, more holistic perception, and different self-enhancement strategies....
Seligman's PERMA model: Positive Emotion, Engagement, Relationships, Meaning, Achievement — the five elements of flourishing. Post-traumatic growth: many people report positive changes following trauma.
Crimial profiling: FBI-pioneered approach to narrowing suspect pool from crime scene. Psychopathy: PCL-R (Hare) measures interpersonal/emotional (callousness, grandiosity) and lifestyle (impulsivity, criminal versatility) factors.
Health behaviour models: Health Belief Model (perceived susceptibility and severity drive health actions), Theory of Planned Behaviour (intention → behaviour mediated by attitudes, norms, control).
Paradox of ageing: psychological wellbeing generally increases across adulthood despite physical decline. Socio-emotional selectivity theory (Carstensen): awareness of limited time shifts priorities toward emotionally meaningful goals
RESEARCH METHODS IN PSYCHOLOGY
True experiments randomly assign participants to conditions — establishing causality. IV (independent variable) manipulated; DV (dependent variable) measured; extraneous variables controlled.
Probability sampling (random, stratified): every member of population has known selection probability — most generalisable. Non-probability (opportunity, snowball): convenient but less generalisable.
Internal reliability: consistency within a measure (split-half, Cronbach's alpha). Test-retest reliability: stability over time. Inter-rater reliability: agreement between observers (Cohen's kappa).
Open Science Collaboration (2015): replication of 100 psychology studies — only 39% successfully replicated. Causes: HARKing (Hypothesising After Results Known), p-hacking (trying multiple analyses until p<.05), publication bias (only significant results published)...
Null hypothesis significance testing: p<.05 means if the null were true, results this extreme occur less than 5% of the time. p-value doesn't measure effect size or practical significance.
BPS Code of Ethics: informed consent, right to withdraw, confidentiality, protection from harm, full debrief. Milgram's obedience study and Zimbardo's Stanford Prison Experiment both violated multiple ethical principles now considered non-negotiable.
Interviews (semi-structured: predetermined topics, flexible exploration), focus groups (group interaction generates data), observation (participant: researcher joins group; non-participant: researcher watches), case studies (in-depth individual analysis), diary studies.
fMRI: indirect measure of neural activity (blood flow). Spatial resolution excellent (~3mm), temporal poor (~5s lag). EEG: direct measure (electrical), temporal excellent (milliseconds), spatial poor.
Meta-analysis statistically combines findings from multiple studies on the same question — increasing power and identifying moderators. Effect size is the common currency.
Popper's falsificationism: science advances by proposing falsifiable hypotheses and attempting to disprove them. Kuhn's paradigms: normal science within a paradigm, punctuated by revolutions.
APPLIED & CONTEMPORARY PSYCHOLOGY
Desirable difficulties: spacing, interleaving, retrieval practice, and elaborative interrogation all enhance long-term learning by making processing harder — counterintuitive findings for students who prefer massed practice ('cramming').
Job satisfaction predictors: autonomy, mastery, purpose (Pink's intrinsic motivation model). Herzberg's two-factor theory: hygiene factors (salary, conditions) prevent dissatisfaction; motivators (achievement, recognition) create satisfaction.
Arousal-performance: Yerkes-Dodson inverted U — optimal arousal varies by task complexity. Mental imagery: motor imagery activates the same neural networks as physical practice.
Consumer decision architecture: nudge theory designs store layouts and menu presentations to shift choices. Scarcity principle: limited availability increases perceived value. Social proof: 'bestseller' labels change choices more than price discounts.
Social comparison theory (Festinger): people evaluate themselves by comparing with similar others. Upward social comparison on Instagram → lower mood, self-esteem, and body image.
Radicalisation models: significance quest theory (Kruglanski): identity significance threatened → significance restoration through extremist group. Moral disengagement (Bandura): mechanisms (dehumanisation, moral justification, diffusion of responsibility) enabling atrocities by normal people.
Adverse Childhood Experiences (ACEs) study (Felitti et al): dose-response relationship between ACE count and adult physical and mental health outcomes — among the most replicated findings in healthcare.
Psychosocial barriers to climate action: finite pool of worry, psychological distance (temporally, geographically, psychologically remote), system justification, optimism bias, single action bias.
Hofstede's cultural dimensions: power distance, individualism-collectivism, uncertainty avoidance, long-term orientation. Matsumoto's emotional experience research: same events produce similar internal emotional states cross-culturally, but emotional expression and regulation rules differ dramatically.
Large Language Models pass the Turing test but fail ToM tests. Social media creates natural experiments with unprecedented scale but questionable random assignment.
FAMOUS STUDIES & DEBATES
Milgram (1963): 65% of participants delivered apparently lethal electric shocks to an actor when instructed by an authority figure.
Zimbardo (1971): Stanford students assigned as 'guards' and 'prisoners' — abandoned after 6 days as 'guards' became abusive and 'prisoners' showed breakdown. Cited as evidence for situational power over character.
Bandura, Ross and Ross (1961): children who saw an adult aggressively attack a Bobo doll (inflatable) imitated the behaviour — more than controls.
Sherif et al (1954): two matched groups of 11-year-old boys at Robbers Cave Summer Camp developed strong in-group identity, then intense intergroup conflict when resources were made scarce.
Rosenhan (1973) sent 8 sane pseudopatients who faked hearing voices to 12 psychiatric hospitals — all admitted, none detected as sane by staff, hospitalised for 7-52 days. Challenged psychiatric diagnosis validity.
Ainsworth's Strange Situation (1970): brief separation from caregiver in laboratory reveals attachment style. Secure (65%): explores when caregiver present, distressed on leaving, easily soothed on return.
Watson and Raynor (1920): infant 'Little Albert' conditioned to fear a white rat by pairing it with a loud noise. Fear generalised to similar stimuli (rabbit, fur coat, Santa mask).
Seligman and Maier (1967): dogs given inescapable shocks later failed to escape when escape was possible — learned helplessness.
Twin studies (Bouchard's Minnesota Twin Study): identical twins raised apart show striking similarities in personality, IQ, religious belief, and even specific habits — suggesting strong genetic contributions.
Freud's enduring contributions: the unconscious (validated by cognitive science), defence mechanisms (operationalised by social psychology), importance of early relationships (attachment theory).
GREAT PSYCHOLOGISTS & THEIR IDEAS
William James — America's first psychologist — asked not what consciousness is, but what it does (functionalism). The stream of consciousness: thought flows continuously without fixed associations.
Pavlov won the 1904 Nobel Prize for digestive physiology — and accidentally discovered classical conditioning while studying it. Dogs salivated to food (unconditioned response).
Skinner showed that voluntary behaviours are shaped by consequences: positive reinforcement strengthens behaviour; punishment weakens it; extinction removes it.
Rogers believed humans have an innate drive toward growth and self-actualisation when provided with facilitative conditions: congruence (therapist authenticity), unconditional positive regard (total acceptance), and empathy (accurate understanding).
Piaget revolutionised developmental psychology by taking children's thinking seriously as different from adults', not just deficient.
Vygotsky (1934): thought and language begin as separate systems and fuse in verbal thought around age 2. Inner speech (silent, abbreviated, syntactically reduced) is the medium of thought.
Asch (1951): participants matched line lengths while confederates deliberately gave wrong answers. 75% conformed at least once; 37% of all responses were conforming.
Festinger's $1/$20 experiment (1959): paid either $1 or $20 to tell another participant a boring task was interesting. $1 participants later rated the task as more enjoyable.
Allport argued against behaviourism: stable internal traits explain cross-situational consistency in behaviour. His lexical hypothesis: trait words in language capture important personality differences.
Elizabeth Loftus has devoted her career to demonstrating that human memory is reconstructive and suggestible. Her research on eyewitness testimony has exonerated innocent people convicted on false memories.
PSYCHOLOGY REVISION
Core assumptions: behaviour is influenced by unconscious processes, early childhood experience shapes personality, and the mind uses defence mechanisms to protect the ego.
Core assumptions: all behaviour is learned through interaction with the environment; only observable behaviour can be studied scientifically; humans and animals differ only in complexity of learning, not in kind.
Core assumptions: mental processes (schemas, attention, memory, language) mediate between stimulus and response; the mind can be modelled as an information processing system.
Core assumptions: behaviour has a biological basis (brain, genetics, hormones, evolution); mind is the product of the brain; understanding behaviour requires neuroscience.
Core assumptions: humans have free will and agency; behaviour should be understood from the individual's subjective perspective (phenomenology); people are motivated by growth and self-actualisation.
Each approach illuminates different aspects: behaviourism explains learned habits and phobias; cognitive explains thinking disorders and educational processes; biological explains genetic transmission and drug action; psychodynamic explains unconscious motivations and defence mechanisms...
Hard determinism: all behaviour is caused; free will is illusory. Soft determinism (compatibilism): behaviour is caused, but deliberate choices are genuinely free in the relevant sense.
Nature-nurture interactionist position: genes express differently in different environments (gene-environment interaction); people select, evoke, and create environments based on genetic tendencies (gene-environment correlation).
Reductionism: explaining phenomena by reference to lower-level processes. Biological reductionism: reduce psychology to neuroscience. Neurological reductionism: reduce to synaptic chemistry.
Alpha bias: exaggerate gender differences (Freud's anatomy is destiny). Beta bias: minimise real differences (using male norms as universal standard). Androcentrism: using male experience as normal.
PSYCHOLOGY IN PRACTICE
Clinical psychologists assess and treat a full range of mental health problems across the lifespan using evidence-based psychological interventions. NICE guidelines specify which therapies have sufficient evidence for each condition.
After brain injury (stroke, TBI, tumour), neuropsychological rehabilitation targets impaired functions through retraining (rebuilding lost skills), compensation (using preserved strengths to work around deficits), and environmental modification.
CAMHS (Child and Adolescent Mental Health Services) in the UK provides assessment and treatment for under-18s. Half of all lifetime mental health conditions emerge by age 14.
Prevention categorised: universal (whole population), selective (at-risk groups), indicated (early signs). Mental health first aid training. ACE-informed parenting programmes. School-based depression prevention (Penn Resiliency Programme).
Intelligence tests: Wechsler scales (WAIS-IV, WISC-V) — IQ as deviation from age-normed mean. Neuropsychological batteries: assess specific cognitive domains. Personality assessment: Minnesota Multiphasic Personality Inventory (MMPI), NEO-PI-R (Big Five).
Practitioners engage in regular clinical supervision — examining their own reactions (countertransference), blind spots, and ethical dilemmas with an experienced supervisor. Reflective practice (Schon): bridge academic theory and clinical experience.
BPS Code of Ethics: respect, competence, responsibility, integrity. Boundaries in therapy: avoiding dual relationships, managing transference and countertransference. Confidentiality: absolute vs duty to protect third parties.
AI systems are increasingly used for psychological assessment (digital phenotyping via smartphone use patterns), chatbot therapy (Woebot: CBT via app, evidence for symptom reduction compared to waitlist), and clinical decision support.
Psychology intersects with: neuroscience (cognitive neuroscience), economics (behavioural economics), law (forensic psychology), medicine (health psychology, psychiatry), education (educational psychology), business (I/O psychology), philosophy (consciousness, free will), computer science (AI and cognition), sociology...
The 'hard problem of consciousness' (Chalmers): why does physical brain activity give rise to subjective experience at all?