Sexual Selection and Human Reproductive Behaviour Flashcards
this gotta b interesting
fuckin finally
What is evolutionary psychology
Explains behaviour in terms of its function and adaptiveness
Extent to which the behaviour enhances the survival and reproduction of the individual’s genes
What is natural selection
idc i hope it kills me soon
nah jk how else r we supposed to make controlled
Gradual process by which nature selects the forms most fit to survive and reproduce in a given environment
The individuals with characteristics that are most suited to the environment are more likely to survive and reproduce
Genes that allowed the individuals to be successful are passed onto the offspring in the next generation
We have evolved adaptive behaviours that ensure our survival
What is sexual selection
Some individuals possess characteristics which do not immediately appear to be beneficial to their survival
Argues that if a characteristics increases the chances of reproduction then the characteristics will be adaptive because the animal will have more offspring
Is the selection of characteristics that increase mating success
What is anisogamy
Humans are anisogamous
Meaning produce gametes of different sizes
What is sperm
yummy
nah
Mobile
What is inter-sexual selection
Preferred choice of females
Where one sex chooses traits they desire in the other sex (e.g. think birds of paradise)
Selection is between the sexes
Quality strategy (selective)
What does inter-sexual selection determiine
Areas in which the other sex must complete
Peacocks = plumage
Humans = economic resources, genetic fitness
These indicators reveal traits that could be passed on to offspring (i.e. selection for ‘good genes’), as well as info about chances of the mate being able to give protection and support to offspring(i.e. selection for ‘good parents’
Human beings are perceptually ‘pre-programmed’ to attend to displays of these important indicators, which in turn increases their willingness to mate with the individual who possesses them
What is intra-sexual selection
Usually males
Competition between members of same sex
Selection is within each sex
Quantity strategy (indiscriminate)
Describe Fisher’s (1930) sexy sons hypothesis
Woman chooses a man because he has a characteristic she wants (e.g. tall male)
Any male children will inherit this characteristic and will be more desirable to women
Over generations the characteristic becomes more pronounced (the runaway process)
This only stops when the trait becomes too costly or female preference changes
What is Zahavi’s (1975) handicap hypothesis
Woman chooses a man with handicaps because it advertises his ability to thrive despite handicaps, demonstrating genetic superiority
e.g. females finding males attractive who drink or take drugs in large amounts - demonstrates an ability to handle toxins, a sign of genetic fitness
What is sexual dismorphism a result of
Mate competition
What is sexual dimorphism
Winners get to mate and pass on their genes
Whatever traits lead to success in these same-sex contests will be passed on to the next generation
Sexual dismorphism concerns the different characteristics that males and fe,ales possess
Males on average 12-15% larger than females
Also includes secondary sexual characteristics
-Males>deeper voice, facial hair
-Females>breasts, hips, smoother skin
These features increase the chances of survival into adulthood and sexual maturity, where genes are passed to the next generation
What is sperm competition
Physically size matters for men
as it does for women
Behaviourally - aggression could work
Compete by producing larger testicles, bigger ejaculations and faster-swimming sperm
What is sneak copulation
Males mate with females other than their partners if given the opportunity as it increases their chances of reproductive success
Women gain from this by having a wider genetic diversity to their children, increasing survival chances
Women can also gain by being in a relationship with a resource-rich male, while copulating with a genetically fit stud
What did Cartwright (2000) say about symmetrical faces
M+W prefer it
Symmetry = reproductive fitness
Also found women with symmetrical breasts are more fertile
And women with symmetrical male partners have the most orgasms
What does Cartwright’s study support
Concept that physical attractiveness is driven by increased ability to reproduce
What is Buss’ 1989 What do women want? study suggests
Conducted large cross-cultural study into human mating preferences
10k people, 37 cultures (33 countries)
Found consistent sex differences
e.g.
M = younger than them, chastity, healthy, good waist to hip ratio
W = good financial provider, ambition and industriousness, tall and strong, older than them, symmetrical face and body
How is sexual selection (evolutionary theory) oversimplified
-ve evaluation
Evolutionary explanation presumes heterosexuality and that all relationships are sexual
Cannot explain couples choosing not to have children, as it assumes all relationships are motivated by a desire to reproduce
What is a +ve evaluation for inter-sexual selection
Clark and Hatfield 1989
Attraction M+F psychology students (confederates) approached opposite sex strangers on a uni campus and asked one of 3 qs
“Would you go out with me tonight?” (50% men, 50% women)
“Would you come over to my apartment tonight?” (69% men, 6% women)
“Would you go to bed with me tonight?” (75% men, 0% women)
Suggests women mate wisely whilst men mate widely
What is a +ve evaluation involving ‘curves in the right places’
Singh (1993 and 2002)
Singh identified waist-to-hip ratio (WHR) as a universally major determinant of attractiveness
Used data from past 50 yrs of beauty content winners and Playboy centrefolds
Small waist and full hips consistent feature
Breast size, overall body weight and physiques varied over time
Optimum WHR = 9.7 (associated with fertility)
What is a +ve evaluation with ‘ovulating lap dancers’
Muller et al (2007)
Most female mammals display oestrus to alert males to receptivity
In humans, oestrus is hidden. Or is it…?
Compared earnings of lap dancers menstruating naturally with those on the pill
During non-fertile periods, both sets of dancers earned similar tips
But when dancers not on the pill entered fertile phase, they earned significantly more tips than pill taking dancers
What is the Waynforth and Dunbar 1995 study
Lonely Hearts
Newspaper ads
+ve research
Content analysis of personal ads in 4 newspapers
470 male, 402 female ads
Waynforth and Dunbar 1995 results
Men =
Indications of material wealth 1.7 times more than women
Men aged 40-49 most likely to express preference for female fecundity (ability to produce young in great numbers)
Women =
Twice as likely as males to advertise their physical attractiveness (curvy, exciting)
Demanded wealth in a partner 4.5 more times than men
Mentioned ‘youth’ more
What is the Campos et al. 2002 ‘Choosy Old Men’ study
Also studied personal ads
As women aged, they became less demanding
Whereas men became more demanding, with age
What is a -ve evaluation regarding how the explanation ignores social and cultural influences
Partner preferences over past century have been influenced by rapidly changing social norms of sexual behaviour
Evolutionary timescales are not as quick as cultural factors such as availability of contraception
What is a study that supports cultural differences
Bereczkei et al 1997
Women in workplace do not depend on men
No longer resource-orientated
Chang et al 2011
Compared partner preference in China over 25 yrs
