

Large testicles are linked to infidelity - thomasfl
http://www.apollon.uio.no/english/articles/2014/infidelity.html

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thomasfl
The article also gives a possible explanation to why humans have oversized
brains. “Just as the elk measures the size of antlers, we humans measure each
other’s brains before we mate,” Peter Bøckman at the University of Oslo
explains.

Two years ago the University of Oslo had an exhibition made by Peter Bøckman
about homophilia in the animal kingdom. The new exhibition, named Sexus, about
sexual behaviour is probably going to be an even greater success.

~~~
dalke
To my knowledge, there is no evidence for the assertion that oversized brains
is based on sexual preference. We see brain size enlargement across many
mammals, and our brains are about what's expected for a primate our size.

The title ("large testicles are linked to infidelity") refers to a trend
across species, but cannot be applied to members of a given species. For
example, the giant panda is taxonomically a carivore, but 99% of what it eats
is bamboo. Just because a skull type and digestive tract is linked to being a
carnivore, doesn't mean that the animal is that.

"The female has also an opportunity to filter out those who will be permitted
fatherhood, for example by having an orgasm." There are dozens of conjectures
about female orgasms. Quoting from Wikipedia's
Orgasm#Theoretical_biological_and_evolutionary_functions :

> They quote primate sexuality specialist Alan Dixson in saying that the
> monogamy-maintenance explanation for female orgasm "seems far-fetched"
> because "females of other primate species, and particularly those with
> multimale-multifemale [promiscuous] mating systems such as macaques and
> chimpanzees, exhibit orgasmic responses in the absence of such bonding or
> the formation of stable family units." On the other hand, Dixson notes that
> "Gibbons, which are primarily monogamous, do not exhibit obvious signs of
> female orgasm.

These observations would suggest that the orgasm/permitting fatherhood
hypothesis is incorrect.

"If you have all your children with one man, influenza may kill all of them.
However, if you mate with the neighbouring male as well, perhaps only some of
the children will perish."

Again, this is one of many conjectures. Another is that women find it
advantageous to sleep with many men because men will help raise their own
children, and will help even if there's only a 25% chance of the child being
theirs.

(Also, I don't think influenza infections are genetic in that way.)

The problem with all of these is that there's no real evidence one way or
another. As a result, it's easy for cultural biases to strongly sway our
interpretations. Take the term "infidelity." That has two meanings: sex with
someone other than one's long-term partner, and the cultural and emotional
expectations, leading to jealousy, that one won't have sex except with one's
partner.

The phrase "We can pledge our fidelity until we are blue in the face" implies
the second is true, but on evolutionary timescales there's no justification
for that belief that people 10,000 years ago followed the same cultural
expectations. We know that different cultures right now do not.

It sounds like the goal of this exhibition is to get people to think about
different possibilities. However, it's also likely that the suggestions
proffered reflect too much of the presenters' own biases rather than the
diversity of hypotheses available.

