Evolutionary explanations for partner preferences

Question 1

Who created the concept of sexual selection?

Answer 1

Darwin

Question 2

What is sexual selection? example

Answer 2

• an evolutionary explanation for partner preferences, through which physical & psychological mechanisms that are beneficial for reproductive success will become more exaggerated over succeeding generations.
  e.g. male peacock’s tail is a sign of genetic fitness- therefore attracts females and is passed down

Question 3

What is human reproductive behaviour?

Answer 3

• This refers to any behaviour which relate to opportunities to reproduce and thereby increase the survival chances of our genes

Question 4

What is the basis of human reproductive behaviour? Define

Answer 4

• anisogamy
  differences between gametes

Question 5

What are the differences between male and female sex cells? list

Answer 5

men:
sperm=small, less energy to be produced, vast in numbers, highly mobile
female:
egg= large, static, produced at intervals for a limited number of fertile years, requires significant amount of energy

Question 6

What is a consequence of anisogamy?

Answer 6

• there is no shortage of fertile males but a fertile women is a much rarer ‘resource’

Question 7

Why is anisogamy important in partner preferences?

Answer 7

• It gives rise to two types of sexual selection

Question 8

What are the two types of sexual selection?

Answer 8

• inter-sexual selection
• intra-sexual selection

Question 9

What is inter- sexual selection?

Answer 9

• refers the strategies used by the female to select a mate ( quality over quantity)
  -Trivers (1972) argues that females are more choosy/selective when it comes to mating

Question 10

Why are females more choosy/selective?

Answer 10

• it requires more energy to produce an egg
  -historically females invest more time/commitment to their offspring

Question 11

What is the runaway process?

Answer 11

• female preference determines which features are passed on to the offspring
• This trait will become more exaggerated over time because it is preferred
  e.g. height would increase in the male pop over generations- each generation females select tallest males -exaggerated

Question 12

What is Fisher’s (1930) sexy son hypothesis?

Answer 12

• female who mates with a male who has a desirable characteristic, then will have sons who inherit this ‘sexy trait’
• sons are more likely to mate successful > ‘sexy trait’ is passed on

Question 13

What is intra-sexual selection?

Answer 13

• refers to competition among members of one sex (typically males) for members of the opposite sex
  -optimum strategy of male (quantity over quality)
  -victors able to pass on their genes while the losers are not
  -attributes which made the male successful > passed on to offspring, helping to ensure their survival & the subsequent passing on of their genes.

Question 14

What does intra-sexual selection strategy give rise to? example

Answer 14

• dimorphism in humans
  > physical differences between men and women
  e.g. -men need to be larger to defeat male rivals
  -female youthfulness is selected> males have preference to mate with younger fertile women (narrow waist, rosy cheeks)

Question 15

What are the behavioural consequences of intra-sexual selection?

Answer 15

• characteristics favoured & passed on are those that allow men to outcompete rivals
  -e.g. intelligence, deceitfulness & aggression
• Males benefit from behaving aggressively to acquire fertile females & protect them from competing males
• leads to selection of aggressiveness in males

Question 16

What research support is there for inter-sexual selection?

Answer 16

• evidence to support female choosiness in partner preference
• Clark & Hatfield (1989) sent male & female psychology students across a campus
  -approached other students with question
• “I have been noticing you around campus. I find you to be very attractive. Would you go to bed with me tonight?”

Question 17

What were the results of Clark & Hatfield’s study?

Answer 17

• 0% of women agreed, 75% of men agreed
• supports the idea that females are more choosier than males when it comes to selecting sexual partners
• males have different strategy to ensure reproductive success

Question 18

What is a counter point to Clark and Hatfield (1989)?

Answer 18

• one strategy adaptive for all males and another adaptive for all females is simplistic
• strategies differ according to length of relationship
• Buss and Schmitt (2016) argue both males & females adopt similar mating strategies when seeking long-term relationships» both sexes are choosy
• more complex & nuanced view of how evolutionary pressures influence partner preferences

Question 19

What research support is there for intra-sexual selection?

Answer 19

• Buss carried out a study of over 10,000 adults in 33 countries
• asked questions relating to a variety of attributes that evolutionary theory predicts are important in partner preference

Question 20

What did Buss find from his research?

Answer 20

• found that females placed greater value on resource-related characteristics than males did (financial prospects & ambition)
• males value physical attractiveness and youth (good reproductive capacity) more than females
• findings reflect sex differences in partner preferences

Question 21

What is a weakness of the evolutionary theory?

Answer 21

• overlooks the influences of social & cultural factors on partner preference
  -partner preferences influenced by rapidly changing social norms of behaviour
• e.g. availability of contraception
  -Bereczkei argues that women’s greater role in the workplace > no longer dependent on men to provide for them - no longer have a resource orientated preference
• partner preferences combo of evolutionary & cultural influences
  -Any theory that fails to account both= limited