There is no "4chan culture" because 4chan has 4 separate and distinct major cultures.
There's /a/ culture, originating with the site in 2003, and consisting of trannyism, namefagging, blogpost/chatroom threads, larping as an anime girl, spamming the same 12 reaction images/"memes" ad-nauseum, calling oneself an "oldfag", and generally being insufferable.
There's /b/ culture, originating circa 2006 with things like "an hero" and the Habbo raid, and consisting of shitposting, OC creation, frog/feels guy posting, not taking oneself or the internet seriously, etc.
There's /pol/ culture, around for ages but really taking off in 2015, consisting of sperging about politics at absolutely every opportunity, taking the internet very seriously, back-and-forth shitflinging about "trannies" and "BBC", lack of any sort of humor or genuine discussion, etc.
There's /int/ culture, similar to /b/ but with a lot of new memes and more absurdist, ironic humor, and /pol/-type shitflinging but a lot more lighthearted and non inherently political.

Most other boards are just syntheses of these base elements.
/bant/ is /a/ culture.
/s4s/ is /a/ with a bit of /b/.
/r9k/ is the blogpost elements of /a/ with the constant seething of /pol/.
/his/ is /pol/ with a bit of /int/.
/qa/ was /int/ with /b/ influences.

There's also arguably general "hobby board" and "porn board" cultures, with the default hobby board just being discussion and the default porn board being dumping porn.
Hobby boards generally develop their own unique cultures when corrupted by a specific major culture, such as /co/ by (lefty)/pol/ or /tv/ by /b/, or remain eternally cultureless like /ck/.
Porn boards have zero culture of note and literally just exist for porn to be dumped. Ironically, this is the fate of /b/.