Social lec 15
Evolutionary fitness : potential to pass on your genes or successfully procreate. You yourself
have to have the ability to survive your mating years, and in order for your jeans to be
propagated, you and your kids need to make it to their mating years.
Reproductive investment: investment of time resources and risk involved in having each child.
Varies between the sexes. The sex that bears the most reproductive costs is “choosier” across
different species. If you invest more time in each offspring you’ll be more choosier than the sex
that does have to.. Wont just mate with anyone, but those who have the better genes.
It’s usually the female. Sex with least productive cost will have more partners and will be in
competition with other mates. Less choosy sex displays greater physical variation. Ex: peacock
Polygamy: several members of one sex mating with one individual with the other sex.
Polygyny: several females with 1 male
90% of mammals that are polygamist do this.
Polyandry: several men with 1 female. See it at times, polygyny is more common.
Seen in polygamy:
Sexual dimorphism: pronounced difference in the size or bodily structures of the 2 sexes.
Monogamy: reproductive partnership that’s based on a permanent tie between partners.
5% of mammals are monogamous.
Men and female of species look the same.
In monogamous couples there is dopamine and oxytocin in nucleus accumbens (where the
recpetors receive dopamine) dopamine is that good feeling, pleasure. The orgasm Is the
strongest surges of dopamine. A lot of addictive drugs act on dopamine. Ex: cocaine that why
you get that pleasure feeling.
It’s the reward transmitter.
Oxytocin it’s a crazy chemical that seems to perform many duties and act chemically. Its an
attachment hormone because it seems to be elicited in attachment events. Ex: surge after
birth, releases milk, sexual climax.
Activation of 1 activates the other. Ex: when you see someone to whom you are attached
release of dopamine. Ex: snort cocaine get attached to it.
Only 5% of mammals have this cooccurence in their brain.
Homosexuality: reproductive partnership between mammals of same sex. Usually associated