human mating strategies. some relevant facts: 1. female investment in offspring – very high male...
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Human Mating Strategies
Some relevant facts:
1. Female investment in offspring – very high
Male investment in offspring – variable
2. Reproductive life
10 20 30 40 50 60 70 80
Female
Male
1. Can humans be shown to mate in a manner consistent with the hypotheses surrounding mate choice by either perception of genetic quality or of ability to provide resources?
Central Question
What should males look for in a mate?
Indicators of fertility (age [youth], health)
What should females look for in a mate?
Indicators of ability to provide resources (age, wealth)
Hypothesis
Women value earning potential more than men
Women value ambition and industriousness more than
men
Men value physical attributes more than women
Men value chastity more than women
Men prefer women younger than themselves
Proportion of cultures supporting hypothesis
0 25 50 75 100
Question: If you could mate with a member of the opposite sex who was no more or less attractive than your permanent mate and there was no risk of disease, discovery or forming a permanent liaison, would you do it?
100
80
60
40
20
0Certainly
wouldProbably
wouldProbably not Certainly not
Probably/certainly not - Females - 91%
- Males - 50%
- Males
- Females
Most primates
Males concentration on mating effort
Females concentration on parental effort
Dominance in a Social Group
Environmental constraints
Group structure
Male strategies Female strategies
Dominance in a Social Group
Underlying principle:
Higher status males more copulations & more offspring
Dominance in a Social Group
Kipsigis
Acres owned
#wives
Dominance in Social Group
12 - 14
15 - 16
17 - 19
Age at puberty
Bride price
52-61 62-71 72-81 82-91
Decade
Ecology of human mating systems
Protein deficiency
Starvation
Subsistence
Female contribution
Marriage system
Population density
Mobility
Group size
Pathogens
Rain predictibility
Rainfall extremes
Temperature extremes
Food storage/trade
Ecology of human mating systems
Protein deficiency
Starvation
Subsistence
Female contribution
Marriage system
Population density
Mobility
Group size
Pathogens
Rain predictibility
Rainfall extremes
Temperature extremes
Food storage/trade
Ecology of human mating systems
Protein deficiency
Starvation
Subsistence
Female contribution
Marriage system
Population density
Mobility
Group size
Pathogens
Rain predictibility
Rainfall extremes
Temperature extremes
Food storage/trade
Ecology of human mating systems
If there are no resources???
Wives
Children
Unokai Non-UnokaiAge
20-24 25-30 31-40 >40
Wives
More wives earlier in life
Unokai – Yanomami warriors (involved in a killing)
Human mating systems
Sperm competitionHow monogamous is monogamy?
Indigo bunting
Days before egglaying
12 0
Extra-pair
Within pair
Human mating systems
Sperm competition
When does it occur?
1. Adolescent courtship
Triobrand Islands
Human mating systems
Sperm competition
When does it occur?
2. Facultative polyandry
polygyny monogamy
polyandryPolyandry
Human mating systems
Sperm competition
When does it occur?
2. Facultative polyandry
polygyny monogamy
polyandryPolyandry
Facultative Polyandry
universal moderate occasional uncommon
Human mating systems
Sperm competition
Why should females be polyandrous?
1. Good genes
2. Genetic Diversity
3. Fertility Backup
- 25% of couples - sterility (35% -male)
4. Material Resources
-females mate extramaritally more often with men of higher socioeconomic status
-females mate extramaritally more often with men older than their primary mate
Human mating systems
Sperm competition
What attributes of humans may have evolved in context of sperm competition?
Males
1. Mating patterns
- most common -monogamy (with extramarital mating?)
-only if cost of any extramarital tactic is free or < cost of supporting second mate
Human mating systems
Sperm competition
What attributes of humans may have evolved in context of sperm competition?
Males
2. Sexual Jealousy and Paternity Assurance
Spousal homocide related to sexual jealousy
USA - 33%Africa (several studies) - 45%
Human mating systems
Sperm competition
What attributes of humans may have evolved in context of sperm competition?
Females
1. Cryptic ovulation and continuous sexual receptivity
Most primates Humans
Human mating systems
Sperm competition
What attributes of humans may have evolved in context of sperm competition?
Females
2. Perennially obvious breasts