It's a counterculture sub-culture that's built on the physical manifestation of low-grade oppositional defiant disorder (ODD) (as opposed to the punk movement which would be a high-grade ODD sub-culture and for which there is lots of cross pollination). It's almost entirely centered around having secret or obscure knowledge from the mainstream which they purposely conflate with "taste" and how those tastes makes them special snowflakes.

Groups of hipsters will "share secrets", which they think keeps that taste special and unique, until some perceived critical mass adopts those same tastes (it makes no different if it comes from within the sub-culture or is coincidentally adopted from without), then they think it dilutes the special uniqueness of those things.

Oftentimes, hipsters will purposely cling onto tastes that might be described as anti-tastes for the purpose of optimizing the search for obscurity - they know the majority of people won't like it if they were exposed to it, therefore it's automatically obscure. This hack also works for producers of hipster geared content, make something tasteless and hipsters are likely to gravitate towards it because of the perceived obscurity.

Tastelessness is not always a hallmark of hipsterism, and is sometimes confused for it. Hipsters rely on obscurity before tastleness. Sometimes virtuoso skills in certain trades of skill sets are also obscure enough, and defiant enough of mainstream tastes, that hipsters may adopt and perfect those skills. For example, ultra high-end foods, in very specific categories, are a hipster staple.

What do normal people care or not care about? Viewing the normal masses as an oppressive authority, their ODD will compel them to adopt the opposite. e.g.

- Normal people don't care where their ketchup is made? Hipsters will hand make ketchup from locally grown organic ingredients of the highest possible quality.

- Normal people want music with a beat and a catchy tune? Hipsters will find music genres composed of random, unmemorable noise.

- Normal people want clothes that fit and go well together? Hipsters will find clothes that don't fit and don't go well together.

etc.

The psychology of special uniqueness gives many hipsters a feeling of power or dominion over other people and can give them an attitude of aloof standoffishness, a "I'm better than you because of the rare things I know about". It can appear a bit like the attitude of "cool". It's also important that the secret knowledge they have is generally not about anything of actual importance. Hipsters won't gravitate towards obscure fields of intellectual study in general -- unless mainstream society expected them not to, then ODD would compel them to.

Hipsters are different from "cool" in that "cool" usually means adoption and mastery of a culture confirming sub-culture and the styles associated with that sub-culture. While hipsterism is focused on adoption and mastery of obscurity.

In some ways, hipsterism is also confused in some cases with nerd culture (and there are some overlaps), except nerd culture cares about topics which lend themselves to obsessive pedant-ism and escapist fiction and may coincidentally appear out-of-the mainstream in similar ways to hipsterism. I'd say it's more likely that hipsterism purposely adopts the appearances of nerdism in some cases because of the obscure non-mainstream guarantees of nerdism (which is often a manifestation of OCD, SPD and ASD, but not ODD).

Obscurity, in the hipster subculture, is also local, rather than global -- which is partially what makes it hard to define. Does the hipster live in a highly urban environment? Then they might adopt rural clothing and fashion tastes. Do they live in a rural environment? Then they might adopt urban wear. Combined with the large long tail of obscurity available to the modern consumer, they have near infinite things to adopt and consume.

Most vexing, hipsterism has difficulty describing itself. It uses words like "authentic" or "rare", but is largely not introspective. A hipster that might care deeply about the authenticity of the 4 pieces 1950s 3-piece jazz band they belong to, cares nothing about the authenticity of the lens-less glasses frames he's wearing. You can bet, however, that his band is the only 1950s 3-piece jazz band in his immediate area. It's the obscurity of the items, the social references, and the assurance that it is not accepted by the authority of the mainstream, to satisfy the ODD urges, that he actually cares about.

Hipsters, in many cases even profess a dislike for each other, possibly because hipsterism takes skill. Anything that takes skill means that somebody can become an authority in it, triggering an ODD reflex against that person. The stereotypical hipster argument of who likes the more obscure band is merely a reflection of this phenomenon.