Chapter 1-7: Evolutionary Theory and Human Sexual Mating

Flashcards covering Darwinian natural selection, sexual selection, parental investment, and the evolved bases of women's and men's mating preferences, including symmetry, scent, body traits, and cognitive biases in mate choice.

What is natural selection as proposed by Darwin?

Traits that help organisms adapt to their environment increase survival and reproduction, making those traits more common in the population over time.

What is sexual selection?

A mode of evolution where traits increase mating success, via male competition or female choice, sometimes at the expense of survival.

What is the 'peacock paradox' in Darwin's theory?

Bright male plumage signals health and good genes and increases mating success, even if it hampers survival.

What are the two engines of evolution discussed in the notes?

Natural selection (survival) and sexual selection (reproduction).

What is Parental Investment Theory and who proposed it?

Proposed by Trivers (1972); the sex that invests more in offspring is more selective, while the less investing sex competes for mates.

Which sex tends to be choosier in humans and why?

Females, due to higher parental investment (eggs, pregnancy, long-term care) and the costs of offspring.

What is the Major Histocompatibility Complex (MHC) and its relevance to attraction?

A set of immune system genes; dissimilar MHC between partners can influence mate choice and may be detected via scent.

What is fluctuating asymmetry?

Small deviations from perfect bilateral symmetry; a cue to developmental stability and genetic health, related to attractiveness.

What does facial symmetry have to do with attractiveness?

Higher symmetry is generally rated as more attractive and findings are robust across cultures and even in monkeys.

Why are masculine facial features potentially attractive?

Masculine features signal higher prenatal testosterone and underlying genetic health, though they may be linked to lower warmth.

What is the mate similarity/dissimilarity effect on attraction in different contexts?

In non-sexual contexts, similarity can increase attraction; in sexual contexts, dissimilarity (DNA differences) is often preferred to boost offspring diversity.

How does scent (MHC) influence attraction?

Women tend to prefer the scent of men with dissimilar MHC to their own, signaling different immune genes and potential offspring health.

What did Thornhill's scent studies demonstrate?

Body odor can signal immune system genetics; women preferred scents from men with dissimilar MHC; the nose detects these cues.

What is mate copying?

The tendency to use others’ mate choices as information; a man with an attractive partner or past relationships can be rated more attractive.

What is the waist-to-hip ratio (WHR) and its significance for men?

Ideal WHR around 0.9; deviations indicate poorer health and serve as a cue to health/status.

Why is tall height attractive?

Tall men are associated with dominance, resources, and higher perceived status; studies link height to attraction and opportunity.

What is the 'V-shaped torso' and its implications for mating?

Broad shoulders with a narrow waist; linked to earlier sexual activity, more partners, and “bad boy” appeal.

How does athletic prowess relate to attraction?

Athletic ability signals health, resource potential, and protective capabilities, contributing to attractiveness.

What is the 'sexy son' hypothesis?

Choosy females preferring attractive males tend to have sons who inherit that attractiveness, increasing grandchildren’s mating chances.

What is the role of male competition in sexual selection?

Males compete for access to mates (e.g., fighting, displays), a key avenue of sexual selection.

How does reproductive biology inequality shape mating strategies?

Females have finite eggs and costly pregnancies; males have abundant sperm, driving different mating incentives.

What is the link between dancing and arousal in attraction?

Dancing raises heart rate and arousal; aerobic activity can serve as a cue to sexual readiness and attraction.

What are some key motivations for sex in humans beyond love or reproduction?

People report a range of motives (fun, emotional connection, insecurity, revenge, etc.); women’s motives can be diverse and context-dependent.

What is the main takeaway about evolution and human attraction?

Attraction is shaped by both natural and sexual selection, with women’s choices guided by signals of good genes, resources, and parental investment, modulated by cultural factors.