We often find religions pushing the idea there is something wrong with the erotic and that it stands in opposition to things like god and religion, which are usually classified as sacred and holy. Generally speaking, religion tends to mark sex as something that should be stayed away from. Why is that exactly?
The answer might lie in the kind of animal that we are.
As far as evolution goes, the reason sex is a private affair for mammals is perhaps because intercourse is a vulnerable period and leaves one open to all kinds of attacks in the wild. Imagine being attacked while aroused (or while taking a dump for that matter).
This is a good read on the matter:
Darwin (1872) argued that shame represents what would be at the primitive level an instinctive seeking for cover, but his elaboration on this wasn’t clear. MacCurdy (1930) took this idea further. He argued that prehistoric man sought concealment for activities which expose him to danger in a hostile environment, e.g., eating, sleeping, sexual intercourse and excretion (Maccurdy, 1930). Concealment was sought prior to the fulfilment of any act that would limit or prevent rapid self-defence. For example, Maccurdy (1930) boldly pointed out that postures during both sexual intercourse and excretion prevents people from rapid self-defence.
Now, on to religion. The religious impulse is to provide human society with a complete framework for life. We have only begun to understand this in recent times, but this framework actually builds on already-existing evolutionary impulses. It tries to cover as much ground as possible, taking into account morality, legality, and suchlike. It even tries to dictate the way sex should happen. And since sex is a private impulse, religion translates that as something that should never be discussed in public or seen by members of society who are not directly involved in the act in its particular instances.
This is where ideas about sex being somehow “unclean” or taboo came from. It came to be associated with things that were the opposite of “holy” and “sacred”. Thus, we see all manner of sexual imagery imposed on ideas like hell — fornication is a Biblical sin, desire is a Buddhist no-no. Women causing the slightest amount of arousal in men is “OMG-WTF-is-this!” in Islam. Hinduism too, despite being more culture and less religion, seems to have assimilated this view of sex despite ancient India having been relatively open-minded in these matters. Kama Sutra anyone?
Here’s the issue though. No matter how much religion prescribes staying away from sex, it can’t go all the way and banish it altogether. Mainly because without sex, there is no “us”. Sex is where everything comes from. So the problem is solved by heaping layer upon layer of mysticism on sex. Like the mystery of cosmic origin, the mystery of individual origin (and gratification) is also treated with ritualistic nudge-nudge-wink-wink. Our cultures acknowledge the importance of sex in rather indirect ways, using rites of passage — there are rituals marking a boy’s becoming a man, or a girl turning into a woman. In some cultures, there are even occasional public celebrations of the sexual impulse.
Owing to this sort of religious and cultural pressure, we often see people grow panicky about how society is losing its moral moorings. If we do not continue to be vigilantly prudish, we are told, people will start having sex in the middle of the road. We are told that openness with respect to sex will cause the very fibre of society to disintegrate and civilisation itself will collapse in a storm of condoms and viagra pills.
This seems unlikely. Given the choice between a comfortable private room and the middle of the road, human beings will always choose to have sex away from the public gaze. We are apes yes, but we are shy apes.