In simple terms
A friendly intro before the formal notes — no formulas yet.
Form it, keep it, or lose it
A personal relationship has three chapters. It starts (formation) for reasons that are partly biological, partly cognitive and partly sociocultural. It is kept alive (maintenance) mostly through how partners communicate. And it can change or end (dissolution) when the balance of fairness or the quality of communication breaks down. Your job in Paper 2 is to explain those chapters WITH research, not just describe the research.
Think of a relationship like a campfire. Getting it lit depends on several conditions at once — a spark (biological attraction), dry tinder that catches easily because it is similar (cognitive similarity), and simply being close enough to the fire to feed it (sociocultural proximity). Keeping it burning depends on tending it — adding fuel and clearing the smoke, which is communication. And it goes out when one person stops adding wood while the other keeps giving everything (inequity), or when the smoke of criticism and contempt smothers the flame.
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Read the command term first: 'Explain' wants a well-supported account; 'Discuss' and 'Evaluate' want that PLUS developed critical thinking.
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Pick the FACTORS the question asks about, then choose one strong study per factor that you can describe and link.
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For every study, state aim, procedure and findings, then say the sentence that turns description into USE: 'This supports the claim that...'.
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Add developed critical thinking — methodology, culture, alternative explanations, or contrasting two factors — and finish with a thesis-driven conclusion.
Explore the concept
Use the live diagram and synced steps — play it or tap a step card to walk through.
Full topic notes
Formal explanation with the rigour you need for the exam.
Formation 1 — biological factors: attraction, pheromones and reward
The biological level treats attraction as partly rooted in physiology and evolved dispositions rather than free choice. One strand is pheromonal: the major histocompatibility complex (MHC), a cluster of immune-system genes, appears to influence body odour, and there is evidence that we find the scent of MHC-dissimilar people more pleasant. The adaptive logic is that pairing with a genetically different partner would give offspring a broader immune repertoire. A second strand is reward: attraction is reinforced when another person's presence activates the brain's dopaminergic reward circuitry (for example the ventral tegmental area), so we come to like people whose company is pleasurable and to associate them with positive feeling — a conditioning account of liking.
Key study (pheromones): Wedekind (1995). AIM: test whether MHC affects odour preference. PROCEDURE: 49 women rated the odour of T-shirts worn for two nights by men who had been MHC-typed. FINDINGS: women rated the odours of MHC-DISSIMILAR men as more pleasant — a preference that reversed for women taking the contraceptive pill.
LINK (use it): this supports the claim that a biological, odour-mediated mechanism biases attraction toward genetically complementary partners, i.e. formation is not purely a conscious choice.
Reward mechanism: neuroimaging of early-stage romantic love shows activation of dopamine-rich reward regions, consistent with the idea that we are drawn to partners whose presence is intrinsically rewarding.
Evaluation: biological accounts can be reductionist and deterministic — they explain a bias, not the whole story, and struggle to explain relationships not oriented toward reproduction. The pill reversal in Wedekind's data also shows the mechanism is not fixed, which is itself a useful critical point.
Formation 2 — cognitive factor: similarity
The cognitive level focuses on how we perceive and appraise potential partners. The best-supported cognitive factor is similarity: we are drawn to — and stay more satisfied with — people we perceive as similar to ourselves in attitudes, values and personality. Cognitively, similarity is rewarding because it validates our own views (someone who agrees with us confirms that we are 'right'), reduces the friction of disagreement, and makes another person feel predictable and easy to understand. This is often contrasted with the folk belief that 'opposites attract' (complementarity), which has consistently weaker support.
Key study (similarity): Markey & Markey (2007). AIM: test whether people want partners similar to themselves. PROCEDURE: surveyed young adults about their ideal partner and, among couples, their actual partners' traits. FINDINGS: participants described an ideal partner similar to themselves (especially in warmth and dominance), and couples who were more similar reported greater satisfaction.
LINK (use it): this supports similarity as a cognitive driver of both formation and satisfaction — we select and stay with partners who match our self-concept.
Evaluation: self-report and correlational designs cannot establish that similarity CAUSES attraction — attraction may create perceived similarity (we assume liked people agree with us). Findings may also reflect Western, individualistic samples where partner choice is comparatively free.
Formation 3 — sociocultural factors: proximity and familiarity
The sociocultural level highlights the surprisingly ordinary conditions that make relationships possible. Chief among them is proximity: we form relationships with the people we are physically and functionally near, simply because closeness creates repeated opportunities to interact. Repeated exposure then breeds familiarity, and via the mere-exposure effect familiarity tends to breed liking. Proximity is a precondition many biological and cognitive factors depend on — you cannot be attracted to, or discover similarity with, someone you never encounter.
Key study (proximity): Festinger, Schachter & Back (1950). AIM: examine how physical arrangement shapes friendship. PROCEDURE: mapped the friendships that formed among residents of a student housing complex (Westgate). FINDINGS: next-door neighbours became friends far more often than residents further apart, and 'functional distance' (e.g. living near stairwells or mailboxes, so you pass more people) predicted who became most popular.
LINK (use it): this supports the claim that a mundane environmental variable — where your front door happens to be — powerfully shapes who you form relationships with, independent of personality or attraction.
Evaluation: the study is a naturalistic field study (high ecological validity) but correlational and from a specific, homogeneous 1950s student population; the digital era, where relationships form online without physical proximity, is a strong contemporary limitation to raise.
The role of communication in maintaining relationships
Once formed, relationships are sustained less by attraction than by how partners communicate. Two processes matter most. First, self-disclosure: gradually revealing personal information builds intimacy, and because disclosure is normally reciprocal, it signals trust — this is the engine of deepening closeness. Second, the QUALITY of everyday and conflict communication. John Gottman's longitudinal observational work on couples identified a cluster of corrosive patterns he called the Four Horsemen — Criticism (attacking character rather than behaviour), Contempt (mockery and disrespect), Defensiveness (refusing responsibility) and Stonewalling (emotional withdrawal). Of these, contempt is the strongest single predictor of eventual breakdown. Gottman also found that stable couples maintain a high ratio of positive to negative interactions even during conflict.
Self-disclosure builds intimacy when it is gradual and reciprocal; a mismatch (one partner over-discloses, the other withholds) undermines trust.
Gottman's Four Horsemen — Criticism, Contempt, Defensiveness, Stonewalling — are communication patterns that predict dissolution; contempt is the most damaging.
LINK (use it): because Gottman could predict later relationship outcomes from observing communication style, communication is shown to be causally central to maintenance, not merely a symptom.
Evaluation: Gottman's core data are correlational/longitudinal, so a third variable (e.g. chronic stress) could drive both the negative communication and the breakup; predictive accuracy from short samples has also been debated. Still, it usefully identifies specific, observable behaviours rather than vague 'poor communication'.
Why relationships change or end: equity theory and breakdown models
Two complementary explanations dominate. Equity theory (Walster/Hatfield and colleagues, 1978) proposes that satisfaction depends on perceived FAIRNESS — the ratio of what each partner puts in to what they get out. Crucially, both being under-benefitted (giving more than you receive, which breeds resentment) and being over-benefitted (receiving more than you give, which breeds guilt) reduce satisfaction. When inequity is felt and cannot be restored, partners are motivated to change or leave the relationship. Duck's phase model of dissolution (1982) then describes HOW ending unfolds — as a process, not a single event — through four phases: the Intrapsychic phase (private dissatisfaction and brooding), the Dyadic phase (confronting the partner), the Social phase (telling friends and family, making the split public), and the Grave-dressing phase (constructing an acceptable story of why it ended).
Equity theory (Walster et al., 1978): perceived fairness, not just profit, predicts satisfaction; chronic inequity motivates change or breakdown.
Duck's phase model (1982): Intrapsychic → Dyadic → Social → Grave-dressing — dissolution as a staged process.
LINK the two (use them together): felt inequity can be the trigger that launches the Intrapsychic phase, showing the theories are complementary rather than competing — a strong Criterion D move.
Evaluation: equity theory may be more predictive in individualistic cultures, where relationships are seen as negotiated exchanges, than in collectivist contexts; Duck's model is descriptive, telling us the stages but not WHY breakdown begins — which is exactly the gap equity theory fills.
Common mistakes examiners penalise
Mislabelling the level of analysis — calling proximity a 'biological' factor or pheromones a 'cognitive' one. Keep it clean: biological = attraction/pheromones/reward; cognitive = similarity/perception; sociocultural = proximity/familiarity/norms. This costs Criterion B (Knowledge).
Arguing 'opposites attract' — writing complementarity as your main claim. The supported factor is SIMILARITY; complementarity has weak evidence and belongs (if at all) as a critical counterpoint, not a thesis.
Describing studies instead of USING them — a perfect account of Wedekind or Festinger with no link sentence scores in Criterion B but leaves Criterion C stranded. Always add 'This supports/challenges the claim that...'.
Evaluation by list — tacking 'it's correlational, it's culturally biased, small sample' onto the end without linking each point to the specific study or argument. Criterion D rewards DEVELOPED critical thinking (explained and relevant), not a bolted-on checklist.
Ignoring the command term — writing a purely descriptive answer to a 'Discuss' or 'Evaluate' question. Without developed critical thinking the essay is capped in the lower bands however much knowledge it shows.
Confusing equity with social exchange — treating 'more rewards than costs' (exchange) as the same as 'fairness of the ratio' (equity). The distinction is exactly where the good critical points live.
Where this leads
Formation, communication and dissolution are one continuous story: the factors that draw people together (biological, cognitive, sociocultural) set the stage, communication determines whether the relationship is maintained, and equity and breakdown models explain how it unravels. Master the discipline this lesson trains — USING research and DEVELOPING critical thinking — and it transfers directly to every other Human Relationships topic (group dynamics, social responsibility) and to Paper 2 as a whole, where the same five criteria decide every essay.
Worked examples
See the formulas applied — reveal one step at a time, like the exam.
Planning task: You are asked, 'Discuss factors influencing the formation of personal relationships. [22]'. In under a minute, choose TWO factors and one study each, and write the single 'use' sentence for one of them.
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Factor 1 — biological (pheromones/MHC): study = Wedekind (1995).
Practice ERQ (8-mark style): 'Explain one theory of why relationships change or end.' Sketch a top-scoring paragraph structure using equity theory.
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Point: One explanation for why relationships end is a loss of equity — the perceived fairness between partners.
Discuss factors that influence the formation of personal relationships. [22]
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Model essay
How it all connects
The big idea sits in the middle — tap a linked idea to explore the link.
Tap a linked idea to see how it connects back to the main topic — that connection is what examiners reward.
Glossary
Try to recall each definition before you reveal it.
Quick check
Answer in your head first — then tap to check. No pressure.
Revision flashcards
Flip the card. Test yourself before the exam.
Personal relationship
A close, interdependent bond between two people, marked by mutual affection, trust and commitment. In IB terms it is studied through formation, maintenance (communication) and dissolution.
Key takeaways
Review these before you close the topic — retrieval beats re-reading.
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Key study (pheromones): Wedekind (1995). AIM: test whether MHC affects odour preference. PROCEDURE: 49 women rated the odour of T-shirts worn for two nights by men who had been MHC-typed. FINDINGS: women rated the odours of MHC-DISSIMILAR men as more pleasant — a preference that reversed for women taking the contraceptive pill.
- ✓
LINK (use it): this supports the claim that a biological, odour-mediated mechanism biases attraction toward genetically complementary partners, i.e. formation is not purely a conscious choice.
- ✓
Reward mechanism: neuroimaging of early-stage romantic love shows activation of dopamine-rich reward regions, consistent with the idea that we are drawn to partners whose presence is intrinsically rewarding.
- ✓
Evaluation: biological accounts can be reductionist and deterministic — they explain a bias, not the whole story, and struggle to explain relationships not oriented toward reproduction. The pill reversal in Wedekind's data also shows the mechanism is not fixed, which is itself a useful critical point.
Practice — then mark it
The whole point: a real Cambridge question, marked mark-by-mark.
Get a Paper 2 essay marked: 'Discuss factors that influence the formation of personal relationships. [22]'
Get a Paper 2 essay marked: 'Discuss factors that influence the formation of personal relationships. [22]'
Extra simulations & links
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Frequently asked
Checkpoint
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Reading it isn’t knowing it — prove it.
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