The Expected Utility of Sex

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Darklight
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The Expected Utility of Sex

Post by Darklight » Tue Dec 02, 2014 3:02 am

Long time no post. XD I've been busy with various distractions in life, and so haven't been as prolific with my silly moral theorizing lately. Nevertheless, I recently had some thoughts about the applications of Utilitarian ethics to everyday life. One particular area that I think is oft overlooked is the question of sex. Historically, notions of sexual morality have a bad rap because we in the more liberal parts of the world tend to think of religiously influenced social conservative views on sex as being matters of disgust and purity, rather than logical, rational considerations. However, I think that Utilitarianism actually does have something to say about sexual choices, and that what it actually entails may surprise you. I should disclaim at this point because of the potential sensitivity of the topic that I am in no way attempting to judge people who might disagree with this particular application of theory. I simply wish to highlight some thoughts that I have had recently on the subject.

So without further adieu, in the tradition of Darklight posting yet another unconventional and possibly controversial application of Utilitarianism, I give you...

The Expected Utility of Sex – A Utilitarian Argument For Conservatism In Sexual Choices

A common naïve view of Utilitarianism is that is exceedingly permissive of consensual sexual relations among adults. After all, sex is pleasurable to both parties, which should make it okay for a hedonistic morality like Utilitarianism right?

A more deep analysis of the potential consequences of sexual relations however shows that it isn’t that simple. Sexual intercourse as an act between male-female partners comes with a non-zero risk of conception of a child. This risk, however small, needs to be factored into the Utilitarian moral calculus.

Assume that a hypothetical pair of consenting adults is responsible and uses contraception. The most commonly used contraception is the male condom, and it has a perfect use 2% failure rate, and a typical use failure rate of 18%. This means that, if we assume the Many-Worlds Interpretation of Physics, that in 18% of universes where you had sex, even with a condom, this caused the consequence of a pregnancy.

This means that the negative utility of unwanted pregnancy needs to be factored into evaluating the merits of every sexual encounter. A brief pleasurable experience in 82% of all worlds must be weighed against all the possible scenarios in which an unwanted pregnancy could occur, including ones that lead to the mother deciding to have the child and the consequences of this. There is a potentially vast amount of negative utility that can occur by introducing a child into this world who is unwanted or unloved. We’re talking about an entire lifetime that is statistically more likely to be below the average in happiness.

This can be mitigated if the unexpected child still ends up in a loving family.

Thus, when calculating the expected utility of sex, one should consider the likelihood that you will eventually marry your sex partner. A simple heuristic is that if you cannot imagine being happily married with this person, you shouldn’t have sex with them. In practice this suggests a policy against one night stands, and recommends that sex should only occur within monogamous relationships, as these are more likely to lead to stable and healthy families.

Stated in the positive, the heuristic is that you should only have sex with someone you would consider marrying in the future, or at least rearing a child together with.

If this is too stringent, a relaxed heuristic is that you should only consider having sex with someone who you would be willing to make child support payments to. Though bear in mind that such a heuristic generates a lower expected utility than the previous heuristic, as children born and raised outside of wedlock tend to lead less pleasant lives.

Now, an argument can be made that certain kinds of sexual relations other than full on intercourse are still acceptable because they have no risk of pregnancy. What should be factored into the considerations of those actions is that they have the potential to create emotional bonds and behaviour that are more likely to lead to full sexual intercourse. It is easy to get carried away in the heat of the moment, so to speak.

Thus, a more nuanced analysis of the consequences suggests that a proper Utilitarian should actually be relatively conservative when it comes to sex.

Basically, whenever you consider having sex with a member of the opposite sex, ask yourself if you want to be responsible for a child with this partner, and decide accordingly, because in some perhaps small percentage of parallel worlds, a child will come into existence.
"The most important human endeavor is the striving for morality in our actions. Our inner balance and even our existence depend on it. Only morality in our actions can give beauty and dignity to life." - Albert Einstein

DanielLC
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Re: The Expected Utility of Sex

Post by DanielLC » Tue Dec 02, 2014 5:22 pm

Can't you just use redundant birth control? If you have sex regularly with just a condom, there is a 2% chance of pregnancy in a given year. This means the actual failure rate is much lower. Using another kind of birth control seems like it could easily bring the failure rate down below 0.001% per year. And there's no reason you have to stop at two. Also, all of this only seems to apply to heterosexual relationships.
Consequentialism: The belief that doing the right thing makes the world a better place.

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Darklight
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Re: The Expected Utility of Sex

Post by Darklight » Wed Dec 03, 2014 4:40 pm

Good catch that the failure rate is in a given year, that was an oversight on my part.

While you could probably bring the risk to an arbitrarily low amount, it will still remain non-zero, meaning that in some parallel universe the pregnancy still occurs. The heuristic moral question is really, do you want to be responsible for this? The proper moral calculus is, does the expected utility, that is to say, the average utility or expected value across all possible worlds end up a net positive or negative? Even if the percentage of worlds is very, very small, the cost of an unwanted pregnancy is arguably so high that it tends to dominate, IMHO.

Of course, you could argue that any kind of risky activity has a non-zero probability of something catastrophic happening. Even just driving a car to go grocery shopping carries a non-zero probability that you might accidentally hit and kill a pedestrian. But saying that we shouldn't ever take the car to go grocery shopping because of this risk seems quite silly. But when you think about it, the utility of grocery shopping is actually much higher because if you don't go grocery shopping, you die of starvation. The better counterexample then is something like taking an airplane to have a pleasant vacation. You can live without the vacation, so the utility is not as high, while the potential loss of the extremely unlikely event of an airplane crash is significant. In non-zero worlds, you die.

So in effect, the expect utility argument can be applied to make one highly conservative and functionally paranoid with regards to every little risk of something catastrophic. At the very least, it suggests that we shouldn't take unnecessary risks. I don't know whether or not such a model is a good way to make decisions, as it seems rather counterintuitive at first glance. It also might suggest such strange notions as lottery tickets being a worthwhile investment, since in a tiny percentage of possible worlds you win...

And yes, the argument as stated only really applies to heterosexual relationships, though I could rework the argument to be about the risk of Sexually Transmitted Diseases like AIDS, and then it would apply to non-heterosexual relationships.
"The most important human endeavor is the striving for morality in our actions. Our inner balance and even our existence depend on it. Only morality in our actions can give beauty and dignity to life." - Albert Einstein

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Brian Tomasik
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Re: The Expected Utility of Sex

Post by Brian Tomasik » Sun Dec 07, 2014 12:35 am

You may have read "The Cost of Kids".
Darklight wrote: The most commonly used contraception is the male condom, and it has a perfect use 2% failure rate, and a typical use failure rate of 18%. This means that, if we assume the Many-Worlds Interpretation of Physics, that in 18% of universes where you had sex, even with a condom, this caused the consequence of a pregnancy.
MWI quantum probabilities for any given couple are very unlikely to track average pregnancy probabilities. If you don't observe a pregnancy to have happened, there is some tiny measure of worlds where totally random stuff caused a pregnancy, but the fraction is 0.0000...0001%, not 18%.

But if you care about expected values, then you don't need fractions of worlds. 18% a priori is still very significant.
Darklight wrote: Thus, a more nuanced analysis of the consequences suggests that a proper Utilitarian should actually be relatively conservative when it comes to sex.
I generally agree, depending how robust your birth control is. STIs are a nontrivial consideration as well, and testing is a lot of work to do properly.

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