The nightime/daytime issue seems to be more an issue of sex being taboo than being a fetish. And one thing that seems clear is that a lot of fetishes specifically revolve around breaking taboos.
Regarding the second issue, keep in mind that the degree of imprinting that occurs when someone is actively having sex is likely to be higher than simply the level of imprinting one would get from simply associating the fetish with sexually attractive images. It might not take more than a few times having sex with a specific fetish for it to imprint. This is further complicated by the fact that some people take sexual pleasure specifically in their partner’s sexual pleasure, so one can have additional imprinting simply if the partner has a pre-existing fetish.
In general, I think we drastically overestimate the level of generalizations that we can make about societies sexual attitudes. Most of the notion of repression → fetishes seems to come from Victorian Britain where things were highly repressed and had a lot of fetishtic behavior, especially BDSM. One reason some terms for BDSM equipment are so ornate is that they date from Victorian times and were sometimes euphemisms or the like. (The most obvious such example is the St. Andrews Cross.)
But other societies that were extremely open about sexuality also has a lot of fetishtic behavior. The ancient Greeks, ancient Romans and ancient Indians are all prominent examples.
Moreover, some societies just have wildly different notions about sex. For example, consider the Jews of the Talmudic time period. They are generally seen as sexually repressed and with good reason. The Talmud discusses how it must be dark when one has sex, and lists probably about 20 or 30 other taboos, some of which seem misogynist. But, a married woman has a right to at least a certain amount of sex a year while a man has no such right. Moreover, the Talmud when discussing non-standard forms of sex outlaws cunnilingus under the logic that if they do it the men will become addicted. To modern thought processes this seems very strange. Moreover, when discussing whether anal sex is permitted with a female on the receiving end, the Talmudic response is that obviously this is ok.
Cultural attitudes about sex and sexuality vary a lot.
The nightime/daytime issue seems to be more an issue of sex being taboo than being a fetish. And one thing that seems clear is that a lot of fetishes specifically revolve around breaking taboos.
Regarding the second issue, keep in mind that the degree of imprinting that occurs when someone is actively having sex is likely to be higher than simply the level of imprinting one would get from simply associating the fetish with sexually attractive images. It might not take more than a few times having sex with a specific fetish for it to imprint. This is further complicated by the fact that some people take sexual pleasure specifically in their partner’s sexual pleasure, so one can have additional imprinting simply if the partner has a pre-existing fetish.
In general, I think we drastically overestimate the level of generalizations that we can make about societies sexual attitudes. Most of the notion of repression → fetishes seems to come from Victorian Britain where things were highly repressed and had a lot of fetishtic behavior, especially BDSM. One reason some terms for BDSM equipment are so ornate is that they date from Victorian times and were sometimes euphemisms or the like. (The most obvious such example is the St. Andrews Cross.)
But other societies that were extremely open about sexuality also has a lot of fetishtic behavior. The ancient Greeks, ancient Romans and ancient Indians are all prominent examples.
Moreover, some societies just have wildly different notions about sex. For example, consider the Jews of the Talmudic time period. They are generally seen as sexually repressed and with good reason. The Talmud discusses how it must be dark when one has sex, and lists probably about 20 or 30 other taboos, some of which seem misogynist. But, a married woman has a right to at least a certain amount of sex a year while a man has no such right. Moreover, the Talmud when discussing non-standard forms of sex outlaws cunnilingus under the logic that if they do it the men will become addicted. To modern thought processes this seems very strange. Moreover, when discussing whether anal sex is permitted with a female on the receiving end, the Talmudic response is that obviously this is ok.
Cultural attitudes about sex and sexuality vary a lot.