The calendar method fails for the same reason condoms 'fail' and coitus interruptus 'fails'.... People don't actually use the method properly. I agree with yo

The calendar method fails for the same reason condoms 'fail' and coitus interruptus 'fails'.... People don't actually use the method properly. I agree with you... if you expect a couple of dumbasses to refrain 100% from allowing semen into the vagina for a week or so during the cycle, you'll end up with a baby. But, for the typical Hacker News user in a monogamous relationship -- that is, a person with an above-average IQ -- the rhythm method is perfectly adequate. It may sound conceited and pretentious, but keep in mind that birth control was invented for idiots who are too simple-minded to pay attention to the absurdly regular cycles that govern ovulation. When you read statistics about the 'failure' rates for certain forms a birth control, keep in mind the sample-size includes folks who literally need directions on how to wear a condom... In short, when we discuss birth-control, let us -- the non-dumbasses -- be aware that what we are really talking about are methods to keep stupid people from having so many babies. I don't know you from adam, but by virtue of you hanging out here, I would expect you and your mate will have precisely the number of kids your were planning to have, without the use of pills, condoms, or vasectomies. Maybe there will be a 'woops' baby once during a long marriage. But, who cares? It's not the end of the world to knock up one's wife by accident. At least not worth the downsides of the Pill in most cases. Once again, if the intent is to have casual sex with many people throughout one's life, then by all means you'll need birth control... even if you're smart. And, apparently, society has decided it is preferable to convince women to take mind-altering pills so that there will be a steady supply of chicks we can bang without fear of consequences, to doing what most human males have done throughout history; namely, aspire to monogamy.