Relationships: Sexual Selection, Attraction, set, Rusbult's Investment Model & Duck's Breakdown

1

Evolutionary Explanations: Anisogamy & Sexual Selection (Trivers, Buss)

Sexual selection (Darwin 1871) arises from anisogamy - the biological difference between male and female gametes: 1. Female gametes (ova) are large, nutrient-rich, and strictly limited in number (produced once a month from puberty to menopause), and females bear a massive obligatory biological investment (9 months of gestation plus lactation: Trivers 1972 Parental Investment Theory). Therefore, females engage in intersexual selection ('female choosiness'), preferring mates with resources, ambition, and commitment who will stick around to protect mother and offspring. 2. Male gametes (sperm) are tiny, mobile, and replenished by the millions daily with minimal obligatory biological investment. Therefore, males engage in intrasexual selection (male-male competition for quantity of mates) and prioritise indicators of female youth and fertility (waist-to-hip ratio ~0.70, smooth skin, neotenous features). Supported by Buss (1989 across 37 cultures and 10,047 participants) and Clark & Hatfield (1989, where 75% of men vs 0% of women agreed to casual sex with a stranger).

Save

2

Factors Affecting Attraction: Self-Disclosure, Physical Attractiveness & Filter Theory

1. Self-disclosure (Altman & Taylor 1973 Social Penetration Theory): Relationships progress via gradual 'onion-peeling' - moving from superficial breadth (sharing hobbies/tastes) to intimate depth (sharing core vulnerabilities and secrets), provided disclosure is reciprocal and appropriately timed (Sprecher & Hendrick 2004). 2. Physical attractiveness: Evolutionary 'halo effect' ('what is beautiful is good' - Dion et al. 1972); however, Walster et al.'s (1966, 1971) Matching hypothesis states that in real life, fear of rejection leads people to choose partners of a similar level of physical attractiveness to themselves (supported by Feingold's 1988 meta-analysis of actual couples, despite Walster's original 1966 'Computer Dance' failing to support matching). 3. FILTER theory (Kerckhoff & Davis 1962): We narrow our 'field of availables' into a 'field of desirables' through three sequential filters: Social Demography (proximity, social class, education, similarity creates accessibility) → Similarity in Attitudes and Values (up to 18 months: Byrne's 1961 Law of Attraction) → Complementarity of Emotional Needs (beyond 18 months, partners whose traits balance each other out).

Save

3

Economic Theories of Maintenance: Social Exchange Theory & Equity Theory

1. Social exchange theory (set - Thibaut & Kelley 1959): Views relationships through a behavioral-economic lens where partners seek to maximise rewards (companionship, sex, status, emotional support) and minimise costs (arguments, stress, financial/time compromise) to make a 'profit' (Rewards: Costs > 0). Satisfaction and stability are judged against two internal standards: Comparison Level (CL): the amount of reward you believe you deserve based on past relationships and cultural norms/media. Comparison Level for Alternatives (CL_alt): whether you believe you could get a higher profit in an alternative relationship or by being single (determines whether you stay or leave). 2. Equity theory (Walster et al. 1978): Critiques set by arguing people do not want to selfishly exploit their partner for maximum profit; instead, they want fairness - where the ratio of (My Rewards / My Inputs) equals (Partner's Rewards / Partner's Inputs). Both the under-benefited partner (who feels resentful and angry) and the over-benefited partner (who feels guilty and ashamed) experience distress (Utne et al. 1984).

Save

4

Rusbult's (1980, 1998) Investment Model of Commitment

Caryl Rusbult refined Social Exchange Theory to explain why some couples stay together even when satisfaction is low (such as in unhappy or abusive relationships). She argued that commitment (which directly drives relationship maintenance behaviors like accommodation and forgiveness) depends on three factors: 1. Satisfaction level (increases commitment when rewards exceed costs and expectations CL); 2. Comparison with alternatives (decreases commitment if attractive alternatives exist); and 3. Investment size (increases commitment): Intrinsic investments are resources put directly into the relationship (time, energy, self-disclosures, money). Extrinsic investments are tangential connections that would be lost if the relationship ended (children, shared home/mortgage, mutual friends, pets). Supported by Rusbult & Martz (1995), who found women at a domestic violence shelter who returned to abusive partners had the lowest satisfaction, but also the poorest economic alternatives (no job/car) and the heaviest investments.

Save

5

Duck's (1982, 2007) Phase Model of Relationship Breakdown

Steve Duck argued relationship dissolution is not a sudden event, but a gradual process passing through four (or five) distinct phases crossed by threshold tipping points: 1. Intrapsychic phase ('I can't stand this anymore'): One partner privately broods on dissatisfaction and the partner's faults, keeping thoughts to themselves or a diary. 2. Dyadic phase ('I'd be justified in withdrawing'): The partner confronts the other, leading to direct arguments, negotiations, and attempts to repair or redefine the relationship. 3. Social phase ('I mean it'): The breakdown goes public; friends and family are told, asked to take sides, or act as mediators, making the split socially irreversible. 4. GRAVE-dressing phase ('It's now inevitable'): After the split, ex-partners construct a face-saving public narrative ('story') that portrays themselves as loyal/reasonable and blames the ex-partner or bad luck to preserve social credit for future relationships. (5. RESURRECTION phase added by Rollie & Duck 2006: preparing oneself for future romantic relationships using lessons learned).

Save

6

Virtual Relationships in Social Media & Parasocial Relationships

1. Virtual relationships (Computer-Mediated Communication - CMC): Reduced Cues Theory (Sproull & Kiesler 1986): CMC lacks non-verbal cues (facial expression, tone of voice), causing deindividuation, bluntness, and low trust. Hyperpersonal Model (Walther 1996, 2011): Online relationships can actually become more intimate and faster-disclosing than face-to-face relationships because senders have asynchronous time for selective self-presentation (curating an idealised self), receivers idealise the partner in the absence of negative cues, and the 'stranger-on-the-train' phenomenon lowers ‘gates’ (obstacles like physical unattractiveness or shyness - McKenna & Bargh 2000). 2. Parasocial relationships (Horton & Wohl 1956): One-sided, unreciprocated emotional attachments where an audience member invests time and emotion into a media celebrity, fictional character, or influencer who is completely unaware of their existence. McCutcheon et al.'s (2002) Celebrity Attitude Scale (CAS) identifies three levels: Entertainment-Social (mild healthy gossip with friends), Intense-Personal (obsessive compulsive feelings that the celebrity is a soulmate), and Borderline-Pathological (extreme fantasising and willingness to commit illegal/stalking acts, explained by the Absorption-Addiction Model and insecure-resistant attachment).

Save

1. Q1

   Outline and evaluate evolutionary explanations for partner preferences, including the relationship between sexual selection and human reproductive behaviour. (8 marks)

   Check Mark Scheme

   Click “Check Mark Scheme” to compare your answer, 1. [AO1 - 4 marks] Evolutionary explanations rest on anisogamy (differences between male and female gametes) and Trivers' (1972) Parental Investment Theory. Because females produce a tiny number of nutrient-rich ova and bear obligatory 9-month gestation and lactation costs, their optimal reproductive strategy is intersexual selection (choosiness): preferring older, ambitious males with financial resources and willingness to invest in offspring. Because males produce millions of tiny sperm daily with minimal obligatory biological cost, they engage in intrasexual competition and prefer young, physically attractive females displaying evolutionary fertility cues (such as a 0.70 waist-to-hip ratio and smooth skin). 2. [AO3 Strength: Cross-cultural and behavioural research support - 2 marks] Buss (1989) surveyed 10,047 people across 37 diverse cultures and found women universally valued financial prospects and ambition more than men, while men in all 37 cultures valued youth and physical attractiveness and preferred younger wives; Singh (1993) also confirmed universal male preference for a 0.70 waist-to-hip ratio. 3. [AO3 Limitation: Social & temporal changes and alpha gender bias - 2 marks] Bereczkei (1997) and Chang et al. (2011, replicating Buss in China across 25 years) showed that as women gain economic independence and gender equality increases, sex differences in mate preferences shrink dramatically (showing social-structural roles matter alongside evolution), and evolutionary theory suffers from alpha bias by exaggerating and excusing male promiscuity.

2. Q2

   Compare Social Exchange Theory and Equity Theory as explanations of romantic relationships. (6 marks)

   Check Mark Scheme

   Click “Check Mark Scheme” to compare your answer, 1. Shared Economic Framework: Both Social Exchange Theory (Thibaut & Kelley 1959) and Equity Theory (Walster et al. 1978) are economic theories that assume partners evaluate relationships rationally by weighing up Rewards (companionship, affection) against Costs (time, effort, stress) [2 marks]. 2. Key Difference (Profit Maximisation vs Fairness): Set claims individuals are selfishly motivated to maximise their own profit (Rewards minus Costs) regardless of what their partner gets, whereas Equity Theory argues that humans care deeply about fairness, seeking an equal ratio of (My Outcomes / My Inputs) = (Partner's Outcomes / Partner's Inputs) so that even being 'over-benefited' causes distress and guilt [2 marks]. 3. Research & Cultural Evaluation: Utne et al. (1984) surveyed 118 newlywed couples and found those who perceived their marriage as equitable were significantly more satisfied than those who were either under-benefited or over-benefited (supporting Equity over set); however, Moghaddam et al. (1993) and Aumer-Ryan et al. (2007) found equity is mainly valued in Western individualist cultures (like the USA), whereas collectivist couples (e.g., in Jamaica) were often happiest when over-benefited [2 marks].

3. Q3

   Describe and evaluate Rusbult's Investment Model of romantic relationships. (8 marks)

   Check Mark Scheme

   Click “Check Mark Scheme” to compare your answer, 1. [AO1 - 4 marks] Rusbult (1980, 1998) developed the Investment Model to address set's inability to explain why dissatisfied couples stay together. She proposed that Commitment (the subjective intention to maintain a relationship, which promotes pro-relationship behaviours like accommodation) is determined by three factors: Satisfaction Level (rewards vs costs compared to expectations CL), Quality of Alternatives (attractiveness of other partners or being single), and Investment Size, comprising Intrinsic investments (time, energy, emotion put directly in) and Extrinsic investments (shared children, house, mutual friends that would be lost upon separation). 2. [AO3 Strength 1: Strong meta-analytic and cross-cultural support - 2 marks] Le and Agnew (2003) conducted a meta-analysis of 52 studies (over 11,000 participants across 5 countries) and found that satisfaction, alternatives, and investment size together accounted for over 60% of the variance in relationship commitment across both heterosexual and homosexual couples. 3. [AO3 Strength 2: Explaining staying in abusive relationships - 2 marks] Rusbult and Martz (1995) studied women in a shelter for victims of domestic abuse and found that those who returned to their abusive partners had the lowest satisfaction, validating Rusbult's claim that high extrinsic investments (children, shared home) and poor economic alternatives (lack of independent income/transport) trap individuals in dissatisfied relationships.

4. Q4

   Outline Duck's Phase Model of relationship breakdown and explain how repair strategies differ between the intrapsychic phase and the dyadic phase. (6 marks)

   Check Mark Scheme

   Click “Check Mark Scheme” to compare your answer, 1. Intrapsychic Phase: One partner crosses the threshold 'I can't stand this anymore' and privately focuses on the partner's faults and weighs pros/cons of leaving without telling the partner [1 mark]. 2. Dyadic Phase: Crossing 'I'd be justified in withdrawing', the partner confronts the other directly, leading to two-way discussions about dissatisfaction, equity, and whether the relationship can be saved [1 mark]. 3. Social Phase: Crossing 'I mean it', the couple tells friends and family, who provide support or take sides, making the split public [1 mark]. 4. Grave-Dressing Phase: After breaking up ('It's now inevitable'), each ex-partner constructs a socially acceptable story that saves face and protects their reputation for future relationships [1 mark]. 5. Repair in the Intrapsychic vs Dyadic Phases (Duck 1994): In the Intrapsychic phase, because the partner hasn't spoken up yet, effective repair involves private cognitive re-evaluation, consciously re-focusing on the partner's positive qualities and re-attributing their negative behaviour to external stress rather than bad character [1 mark]. 6. In contrast, in the Dyadic phase, repair requires active behavioural communication between both partners, negotiating new rules, redistributing household chores, or attending couples counselling [1 mark].

Related study guides