IB DP Psychology: Option: Psychology of human relationships – Revision Notes

Course note: these notes follow IB DP Psychology for first assessment 2019, whose last examination session is November 2026. The replacement course is first assessed in May 2027.

The psychology of human relationships is one of the four IB DP Psychology options, examined on Paper 2 through 22-mark essays. It covers personal relationships (how they form, how communication shapes them and why they change or end), group dynamics (co-operation, competition, prejudice and conflict) and social responsibility (bystanderism and prosocial behaviour), using research from all three approaches.

Related: Human relationships study guide and practice questions.

Syllabus coverage (first assessment 2019)

Topic	Content
Personal relationships	Formation of personal relationships; role of communication; explanations for why relationships change or end
Group dynamics	Cooperation and competition; prejudice and discrimination; origins of conflict and conflict resolution
Social responsibility	Bystanderism; prosocial behaviour; promoting prosocial behaviour

Personal relationships

Content	Explanation	Research
Formation	Proximity, similarity, physical attractiveness, evolutionary preferences, neurochemistry of attraction	Festinger, Schachter and Back (1950): friendships in a student housing complex formed most often between neighbours; Buss (1989): across 37 cultures men valued youth and attractiveness more, women financial prospects; Fisher et al. (2005): fMRI showed dopamine-rich reward areas activated by photos of a loved partner
Communication	Patterns of interaction and attributions affect satisfaction	Gottman’s “four horsemen” (criticism, contempt, defensiveness, stonewalling); Buehlman, Gottman and Katz (1992): oral-history interviews predicted later divorce with high accuracy; Bradbury and Fincham (1990) on relationship-enhancing and distress-maintaining attributions
Change or end	Costs and rewards, investment, comparison with alternatives	Rusbult’s investment model: commitment depends on satisfaction, quality of alternatives and investment size

Group dynamics

Content	Explanation	Research
Cooperation and competition	Realistic conflict theory: competition for scarce resources creates hostility; superordinate goals create cooperation	Sherif et al. (Robbers Cave, 1954): boys at a summer camp formed hostile groups during competition; shared goals reduced conflict
Prejudice and discrimination	Social identity theory; stereotypes	Tajfel et al. (1971) minimal groups; Bertrand and Mullainathan (2004): CVs with White-sounding names received more interview callbacks than identical CVs with Black-sounding names
Origins of conflict and resolution	Competition, identity threat; contact and cooperation	Allport’s contact hypothesis (1954): equal status, common goals, institutional support; Aronson’s jigsaw classroom: interdependent learning reduced prejudice

Social responsibility

Content	Explanation	Research
Bystanderism	Diffusion of responsibility; Latané and Darley’s decision model (notice, interpret, take responsibility, decide how, act); arousal: cost-reward model	Darley and Latané (1968): participants who believed they alone heard a seizure helped far more often and faster than those who believed others heard it; Piliavin et al. (1969): a victim with a cane was helped more often than one who appeared drunk
Prosocial behaviour	Empathy-altruism hypothesis versus egoistic explanations; kin selection	Batson et al. (1981): high-empathy participants helped even when escape was easy
Promoting prosocial behaviour	Modelling, media, education, reducing anonymity	Research on prosocial television content, such as meta-analysis of children’s programming effects

Methods and ethics across the option

Method	Example	Evaluation
Field experiment	Robbers Cave; Piliavin’s subway study; the CV study	High ecological validity; consent and debriefing often impossible
Laboratory experiment	Darley and Latané; Batson et al.; Tajfel’s minimal groups	Control and replicability; deception and artificial tasks
Survey and interview	Buss’s cross-cultural survey; Gottman’s oral-history interview	Large or rich data; self-report bias
Brain imaging	Fisher et al. (2005)	Biological correlates; small samples and correlation only

Worked example: applying the decision model

A student passes a classmate crying in an empty corridor, and later a stranger lying on a busy street.

• Notice: both noticed; on the busy street, distractions reduce noticing.
• Interpret: crowd inaction suggests “not an emergency” (pluralistic ignorance).
• Responsibility: alone in the corridor, responsibility is clear; on the street it is diffused.
• Decide and act: cost-reward judgement – knowing the classmate lowers costs.

The model predicts help is more likely in the corridor, as Darley and Latané’s findings suggest.

Common mistakes / exam traps

• Formation essays on one factor only. Show a range of factors and evaluate their relative importance.
• Treating Robbers Cave as a lab experiment. It was a field experiment with a small, homogeneous sample of boys.
• Using evolutionary findings without cultural evaluation. Buss’s data are self-report preferences, and gender equality varies across cultures.
• Bystander essays that only describe studies. Explain the mechanism: diffusion of responsibility, pluralistic ignorance, cost-reward.
• Ignoring the question’s focus on “promoting”. Promotion questions need interventions, not just explanations.

Frequently asked questions

How is this option examined? On Paper 2: three 22-mark ERQs are set on each option; you answer one (SL) or one from each of two options (HL).

Is prejudice here the same as in the sociocultural approach? The concepts overlap, but this option asks about prejudice and discrimination within group dynamics and conflict resolution; link research to conflict and its reduction.

Which ethical issues come up? Deception and harm in bystander studies (Darley and Latané; Piliavin), and in field experiments without consent, such as the Robbers Cave camp.

Self-test

1. What is diffusion of responsibility? The reduced sense of personal responsibility to help when others are present.
2. Name Gottman’s four horsemen. Criticism, contempt, defensiveness, stonewalling.
3. What are superordinate goals? Goals that require groups to cooperate.
4. What does Rusbult’s investment model predict? Commitment rises with satisfaction and investment and falls with attractive alternatives.
5. What did Batson et al. (1981) test? Whether empathy produces altruistic helping even when escape is easy.