Chapter 7: Primate Mating Systems

1
Chapter 7 Primate Mating Systems

• Mating Systems are patterns of reproductive
  strategies between females and males within a
  species.
• Mating effort finding a mate, bonding between
  sexes (monogamy, polygyny, polyandry, harems,
  multi-sex, etc.,)
• Parenting effort caring and provisioning of
  offspring (mother only, mother and father,
  alloparental care or cooperative breeding)

2
Behavioral Adaptations or Strategies

• Strategies
• are behavioral adaptations (designed by natural
  selection to solve ESP).
• weigh the cost and benefits of alternative
  behaviors that address the same functional
  problem (of opportunity).
• Mating strategies are reproductive adaptations

3
       Trivers Parental Investment Theory

• The sex who invests most will be most selective
  in mate choice inter-sexual selection
• The sex who invests the least will be more
  competitive for sexual access intra-sexual
  selection
• Go to a bar . . .
• Peacock tails and the power of female mate
  choice inter-sexual selection.
• Better providers and sexier sons

4
Big-Mama theory and Seahorses
5
What criteria do Women use in choosing a long
term mate?

• Wealth ability to invest

6

• Dragonfly love
• Future earning power
• Generosity willingness to invest in wife in kids
  
• Economic fidelity
• Protection size, bravery and skill
• Predators
• Other men
• Holding on to resources
• Technological skills

7
Status

• More resources and able to hold on to resources
• Political and physical protection
• Higher status children
• Power is the ultimate aphrodisiac and the
  Hill-Side Strangler
• Hypogamy
• Cultural and environmental standards for success
  criteria
• Dilbert and Computer Nerds
• Physical size
• Age is a proxy for wealth and power
• Cultural differences

8

• Good father
• Teach skills to sons
• Help teach daughters to recognize high quality
  males
• Potential
• James Dean and rebels without a cause
• Ambition vs. laziness
• Cant trust a flake!
• Undependable
• Emotionally unstable or immature
• Less likely to bet the family fortune on a
  football game
• Less likely to be insecure and physically abusive
  
• Less likely to leave them for another woman.

9

• Athletic Prowess offers cues to
• Ability to acquire resources
• Protection
• Status
• Taller men
• Earn more money
• Win elections
• More attractive

10
(No Transcript)
11

• Symmetry
• Better able to invest
• Healthier children

12

• Men with babies, dogs, other women cues of
  willingness to invest
• Women with money structural powerlessness
  hypothesis
• Not just wealthy powerful men are more
  attractive, but a thermostatic like mechanism
  for cutting the best deal
• What about Madonna?
• Beckers divorce rate study

13
Husbands vs. Studs

• Good behavioral traits over good looks for
  husbands
• Women in long-term relationships more likely to
  go for good traits

14
What do Men Look for in a Long-term Mate?

• Guinness Book of Records Moulay Ismail the
  Bloodthirsty (1672-1727), emperor of Morocco was
  reported to have killed 30,000 people with his
  own hands, and had 888 children, 4 wives and a
  harem of 500 concubines. His senior wife managed
  the harem for him. Each concubine had her own
  eunuch and a personal female slave. They were
  forbidden to visit even among themselves and when
  one Westerner was visiting the emperor 14
  concubines who had been caught visiting each
  other had all of their teeth pulled out as
  punishment. They were shipped out to an
  underlings harem when they turned 30.

15

• Precolonial kingdoms of Africa the Ashanti,
  Azande, Baganda, and Zulu Kings are reported to
  have had harems of over a thousand women, so too
  did harems in India, China and in the Muslim
  world.
• Chinese imperial harems of a thousand women had
  well managed copulation schedules on a rotating
  basis according to menstrual cycle.
• In the early 1900s an Indian potentate was
  reported to have had 4 children born in 8 days
  with 9 more due the following week.

16

• This kind of power is very recent in evolutionary
  time and could not have led to evolved
  psychological mechanisms.
• Yes but
• Demonstrates evolved male desires.
• Men with unleashed power can do what they want
  and this is what they want.
• Powerful men in tribal societies may not have had
  the opportunity to have sexual access to
  thousands of women, but many had two, three, four
  and more times the number of wives than did less
  powerful men.
• e.g., Shinbone, Yanomamö head man and renown
  warrior had 11wives, 43 children, 231
  grandchildren, and 480 great-grandchildren with
  more to come.
• Wilt Chamberlain, and Magic Johnson?
• Year of the documentary at Sundance

17

• Women seek men who commit or at least can
  convince them that they are committed.
• In the past men who would not commit or cheated
  would be well known, modern societies allow for
  more anonymity.
• Men who were in committed relationships had
• Greater paternal certainty.
• Children with greater survival rates.
• Prediction in environments with lower childhood
  mortality (richer environments) more men will
  pursue a short-term strategy, i.e., less
  committed, cheat.
• Greater chance of marrying well
• Children with a greater chance of marrying well

18
If men are going to commit they should also be
choosy

• Beauty is in the adaptations of the beholder
  (Symons)
• Universal standards of beauty
• Preference for beauty in infants (pre-socialized
  children)
• Unlike other primates, women are hyper-sexually
  attractive

19

• Men are attracted to woman who show cues of
  greater fertility
• Cues of health
• Skin tone and complexion
• Cultural differences in skin color
• Clear eyes
• Healthy hair
• Symmetry

20

•    Cues of youth
• Hey nine-teen (Steely Dan)
• Neotonous features
• Smaller lower face
• High check bones
• Smaller jaw
• Bigger eyes
• Smaller mouth with fuller lips
• Anti-gravity
• High check bones again
• Lack of sagging skin and body parts (bras)

21

• Average features
• Hip-Waist ratios
• Cues of ovulation
• Good for short term mating but more complicated
  when also calculating in commitment
• Lighter skin
• Rosy cheeks
• Also smells (The Scent of Eros)

22

• Makeup mimics cues of health, youth, and
  ovulation.
• Behaviors that are attractive
• Cues of youth, health, and ovulation
• Cues of paternal certainty
• Virgins (sex differences in preference)
• Cultural differences
• Sluts
• Controllable?
• Smaller
• Naive or flaky
• Not assertive
• Earn less money?

23
In short Men want physically attractive, young,
sexually loyal wives who will remain faithful
until death.
24
Short-Term Sexual Strategies

• The benefits to men are clear, but what are the
  costs?
• STDs
• Risk of losing long-term partner
• Lower ones opportunity for marriage
• Lower chance of attracting a high quality mate
• Wife my leave you or have affairs
• Revenge
• Risk management
• Increase mortality of ones children
• Richer environments would favor short-term
  matings

25

• Wealth/Status effects on benefits
• Violence
• From husband
• From womens kinspeople
• From your kinspeople
• From wife
• A well deserved reputation for fierceness will
  favor short-term matings
• Loss of alliances
• Womens kin mad
• Your kin

26
What are the adaptive problems associated with
male short-term strategies?

• Finding willing partners
• Short-term mates often have qualities opposite
  those of long-term mates
• Avoiding commitment
• Avoiding expensive investment
• Avoiding or minimizing the costs mentioned above.
  
• Maximizing the benefits
• Immediate fertility cues not long-term fertility
  values

27
Evidence of adaptations for male short-term
mating strategies

• Men have lower mate quality standards
• Sperm wars
• All the old stuff, testis size, Kamikaze sperm
  etc.
• Sperm count and separation
• Some thoughts Chimp past, are mens testes
  getting smaller, how might birth control effect
  sperm competition
• Men have greater sex drives
• The Coolidge effect is evidence of section on men
  for short-term mating strategies. Men on average
  desire 4 times the number of lifetime sexual
  partners
• More willing to have a causal sexual encounter
  with a stranger
• Men are self-deceptive about choosiness.
• Men have more extramarital affairs
  (cross-cultural/universal)
• More willing to pay for sex (cross-cultural/univer
  sal)

28
Sex Differences in Sexual Fantasies

• Uncommitted sex
• Variety
• Quantity
• On demand
• Lust not love of emotional attachment
• The most striking feature of (male fantasy) is
  that sex is sheer lust and physical
  gratification, devoid of encumbering
  relationships, emotional elaboration, complicated
  plot lines, flirtation, courtship, and extended
  foreplay (Ellis Symons)
• In contrast, women tend to fantasize about
  familiar partners typically someone they are
  already involved with, and with high
  emotional/romantic content.

29
Evidence for female cognitive adaptations for
short-term matings
Although they have less reproductive incentive,
women also derive benefits from short-term
matings. If they did not, men would not have
evolved adaptations for sexual variety

• Orgasm up-suck hypotheses
• Extramarital affairs (near universal)

30

• Paternal confusion
• More resources and protection
• Chimps yes, but people?
• Sleeping ones way to the top
• Exchange for goods and services
• Sleeping with the boss for a promotion
• Social climbing
• Groupies
• Mate Switching Hypotheses
• Mate Skill Acquisition Hypotheses
• Maybe women can hone skills of seduction without
  going all the way
• Mate Manipulation Hypotheses
• Revenge
• A woman can manipulate by flirting with other men
  and not incur the cost of getting caught in an
  extramarital affair.

31
Short-term mating costs to women

• Reputation      
• As with men but more so
• Lower chances of securing a high-quality
  long-term mate
• Higher childhood mortality
• If in long-term relationship (married) lower
  paternal certainty can lead too less paternal
  investment.
• paternal confusion may lead to lower overall
  support
• Violence
• Angry husband (book omits this)
• Unattached women more likely to be abused by men

32

•   Number one reason women give for having an
  affair is sexual gratification
• Variables that increase likelihood of short-term
  matings (contexts that lead to lower costs and
  higher benefits)
• Age
• Life history
• Sex ratios (density dependent strategies)
• Mate value
• In short cutting the best deal
• Men with more choice peruse sexual variety (less
  choosy).
• Women with more choice seek long-term commitment
  from high-quality men (more choosy).

33
Conflicts between women and men over sex are
inevitable because men and women are pursuing
different, often conflicting, sexual strategies
(Strategic Interference Theory)

• Conflicts arise over
• Sexual Access
• The timing and frequency of sex (sexual control)
• On average men are more sexually aggressive
• Sexual withholding
• Women more than men
• An aspect of choosiness
• Scarcity increases value
• Increase value means men are more willing to
  invest and invest more (commitment dont buy
  the cow if you already get the milk free

34
Different perceptions about the sexual intent of
the other
35

• Deception about commitment
• Sexual harassment in the work place is common
  because
• Status differences in the evolutionary past often
  led to sexual control differences
• Corporate/Workplace hierarchies (CEOs, Pres.,
  VPs, on down to low level personal) are perceived
  as dominance hierarchies by our evolved cognitive
  mechanism (Miss-Match Theory)
• Men are more likely to pursue mate-retention
  tactics including violence

36

• Mate Deprivation Hypothesis
• Men who are less able to compete for the
  resources and status necessary to attract women
  turn to sexual aggression so not to be excluded
  entirely from reproduction.
• Hypothesis was falsified!

• Correlated with mens perception of future
  earning potential

37
Sexual Jealousy

• Men and women experience sexual jealousy in about
  the same magnitude and frequency
• Different triggers
• Sexual infidelity (60 of Men, 17 of women)
• Emotional involvement (cues of long-term
  diversion of investment) (83 of women, 40 of
  men) but honey it was just sex she doesnt mean
  anything to me
• Cross-cultural

38
Variables affecting mate-retention tactics

• Likelihood of infidelity
• Womens reproductive value
• Age
• Physical attractiveness
• Mens income and Status
• Higher income
• Effort towards status striving
• Mate value differentials
• She gets older he becomes distinguished
• Jealous of younger women
• He looses job or doesnt realize potential
• Jealous of higher status men

39

• Men more willing to resort to violent tactics
• Violence must have worked in the EEA
• Mate preferences and intra sexual competition
• Each sex, through mate choice, defines the nature
  and goals of competition for the other sex.
• Men value physical appearance in women so women
  compete with each other with in the domain of
  physical appearance
• Women value status and resources in men so men
  compete with each other for status and resources
• Conflict between the sexes is then linked to same
  sex conflict
• Blame the victim?
• Media

40
Parental motivation

• Psychological literature is lacking.
• Evolutionary Theory predicts self-sacrifice for
  sake of offspring.
• Evolutionary Theory leads us to ask questions and
  examine assumptions that other theoretical
  frameworks either ignore or take for granted.
• The ultimate reason that parents love their
  children, will expend lots of energy on behalf of
  their children, and take great risks to protect
  them, is because in the evolutionary past those
  individuals that did these things and did them
  well had more children survive to have children
  of their own than did those individuals that did
  not do these things or who did not do them as
  well.

41
Mothers are primary caretakers because

• When a mother calculates the costs and benefits
  of how much to invest, or whether or not to
  invest, in a particular offspring she is weighing
  the reproductive value of this offspring against
  the reproduction value of existing offspring or
  future offspring.
• Most insects and fish strategies is to not invest
  in offspring beyond laying and fertilizing eggs
  and perhaps a onetime investment to start them
  off, and instead put their energy into having
  lots of offspring each with low chances of
  survival.

42
When a father is making the same calculation he
must also factor in

• the possibility that this offspring my not be his
  (PATERNAL UNCERTAINTY HYPOTHESIS)
• whether or not his investment is critical to this
  childs survival and future success
  (ABANDONABILITY HYPOTHESIS)
• and the reproductive potential of investing (or
  continuing to invest) in the children he has with
  this mate vs. his opportunity to invest in
  offspring with an other mate with greater
  reproductive potential (MATING OPPORTUNITY COST
  HYPOTHESIS)

43
Paternal uncertainty theory

• Females know (with the exception victims of
  cuckoos and other parasitic breeders)
• Male Seahorses know
• If there is a chance that the child is not his,
  he will factor in the paternal uncertainty
  percentage as an additional cost
• Matrilineal societies

44
Abandonability theory

• The odds that the child will survive with only
  one provider.
• And knowing that since the female will have more
  invested, and that one child represents a larger
  proportion of total reproductive potential for a
  female, she is less likely to abandon the child
  and is therefore forced to care for the child
  rather than let him/her die.

45
Mating Opportunity Cost Hypothesis

• Males calculate the odds of survival for each
  offspring vs. benefits of investing in short-term
  mating or long-term mating with another female
  with a higher reproductive value (7 year itch?)

46
What are the cost and benefits associated with
parental care decisions?

• Parental care mechanisms, like other
  psychological mechanisms, are innate strategies
  for making decision and motivating behaviors that
  weigh the ultimate reproductive costs and
  benefits of alternative behaviors (proximate
  mechanisms).
• This leads us to ask what are the relative
  variables and/or contexts that are likely to be
  important or salient inputs for parental care
  decisions?
• 1.     Genetic relatedness of offspring (KIN
  SELECTION)
• 2.     Ability of the offspring to convert
  parental care into fitness (RETURN FOR UNIT OF
  INVESTMENT)
• 3.     Alternative uses of the resources
  (WEIGHING DIFFERENT RETURNS FOR DIFFERENT
  INVESTMENTS)