HUMAN REPRODUCTION BIOLOGY 269

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HUMAN REPRODUCTIONBIOLOGY 269
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Previous lectures discussed how anatomy
physiology of the human reproductive system and
how human sexual response are evolutionarily
adapted for specific reproductive strategies.
Human reproductive behaviors are also the
product of adaptation.
Adapted to
Send and respond to signals indicating readiness
for sex Select healthy mates carrying most
desirable traits Reproduce during our strongest
and healthiest years Reproduce as frequently as
possible Maximize probability that each
intercourse will result in fertilization Maximize
probability that both mother and young will
survive pregnancy Maximize probability that
offspring will reach maturity and reproduce
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While much human reproductive behavior is the
product of evolutionary adaptation, much of it is
also learned.

• To a large extent, learned reproductive behaviors
  are directed toward the same goals as those which
  have evolved
• Send and respond to signals indicating readiness
  for sex
• Select healthy mates carrying most desirable
  traits
• Reproduce during our strongest and healthiest
  years
• Reproduce as frequently as possible
• Maximize probability that each intercourse will
  result in fertilization
• Maximize probability that both mother and young
  will survive pregnancy
• Maximize probability that offspring will reach
  maturity and reproduce

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Learned sexual / reproductive behaviors are
strongly influenced by cultural and social
conditions.
Examples Different cultures have different
types of dress, music, dance, speech, etc. which
indicate Im looking for a mate or I am
specifically interested in you Different
cultures have different standards of what are
desirable traits Different cultures have
different mating or marriage customs such as
polygamy (multiple wives), polyandry (multiple
husbands), homosexuality Different cultures have
different attitudes toward sex inside and outside
of marriage - often different attitudes for men
vs women Different cultures have different
attitudes regarding sex for pleasure vs sex for
reproduction Different cultures have different
attitudes about how children should be raised
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(Reproductive behaviors influenced by cultural /
social conditions)
(Examples) More affluent people within a
society often have different sexual attitudes and
behaviors than less affluent people in the same
society Rural areas of a country often have
different sexual attitudes and behaviors than
urban areas of the same country Older people
often have different sexual attitudes and
behaviors than younger individuals Sexual
behaviors are often used for things other than
reproduction, e.g. companionship status or
power economic security
In many (but not all) cultures, sexual attitudes
and behaviors are shaped by religion
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Human sexual behaviors, like all animals
sexually dimorphic (different forms in males vs.
females)
While many differences, also many similarities
with same objectives

• Select healthy mates carrying most desirable
  traits
• Send and respond to signals indicating readiness
  for sex
• Reproduce during our strongest and healthiest
  years
• Reproduce as frequently as possible
• Maximize probability that each intercourse will
  result in fertilization
• Maximize probability that both mother and young
  will survive pregnancy
• Maximize probability that offspring will reach
  maturity and reproduce

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• End result Sexual behavior must be viewed
  contextually We can not define normal or
  typical reproductive attitudes and behaviors
  without first

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