We do that here too. Think of when people bring up the phrase "if it's free then you are the product." The first few times it's seen by people, they think that's a great way to describe what they're seeing, and it spreads like wildfire. Now it's to the point I groan when I inevitably see it during a discussion.

This is really just the propagation of ideas which have sex: https://www.wired.co.uk/article/ideas-having-sex-matt-ridley...

In an attempt to appear unique, everyone ends up doing the same thing.

Instagram is just a reflection of what society does in real life. This is visible in fashion, hair styles, beard, and whatever is the trend now.

I personally don’t understand why so many people have this need to look like their peers. Does anyone with more social skills have an explanation?

It's pretty simple, and really not caused by people attempting to appear unique. There are two main factors: 1. All humans has a need to be accepted and approved of by their peers, 2. Humans also have an essentially identical neural architecture and a very similar set of likes and preferences to their peers. This results in groups of people with similar habits, clothes, and so on. The vast majority of humans normally want to fit in and conform, rather than be the odd one out in a group, see the entry on tribalism in any good anthropology textbook.

Also, anyone who claims not to understand this is either lying, engaging in some form of virtue signalling or has some sort of mental illness.

Related to 2: sellers actively exploit our preferences, which probably creates a feedback loop where we buy the same kinds of clothes, accessories, etc.

I'll add a third, more mundane option, somewhat related to 2: default behavior. I think we generally prefer to do whatever takes the least amount of effort, and comforming is generally easier than the alternative.

> Also, anyone who claims not to understand this is either lying, engaging in some form of virtue signalling or has some sort of mental illness.

Let’s assume you are right and there are only these three possibilities, what kind of mental illness would you suggest I have?

Since I was a little kid it never appealed to me to do what most of my friends were doing just because they were doing it.

A fourth option would be that I never cared about it enough to actually look for the reasons.

I'd suggest that if you genuinely don't understand this sort of social thing instinctively, then you're probably on the autism/aspergers spectrum then. I really wasn't trying to be offensive towards you or anything, I just probably forgot some extra caveats... Basically, this sort of social reasoning is (usually) hard wired into your (typical) human being, and has been since prehistory. But mental disorders like autism seem to mess up social perceptions and interactions, masking these instincts. Fortunately, in that case, I've found it's possible to work around the issue by simply researching what the natural instincts and drivers are for the typical human, hence my suggestion of referencing an anthropology textbook.

But take computer games, for instance. The main character (or any important character) is usually very different from everyone around them. Both in the way they act, but also the way they look. Nobody wants to play as the NPC.

To me, that applies to real life as well. But it would seem that a lot of people want to stand out in a video game/movie/book etc., but conform in real life?

Not everyone can be the protagonist in real life, but they can imitate a prominent person and thereby associate themselves with that person's success and prestige. It's a variety of narcissism in which less successful people deal with their narcissistic urges by becoming "followers".

See https://en.wikipedia.org/wiki/Collective_narcissism#The_char...

There are obvious disadvantages to being the PC -- your life is not stable or safe. In real life, there are no save points. It's not so surprising that people live real life as an NPC, but fantasize about the excitement of being a PC, and consume media that allows them to indulge that fantasy without risk.

> In an attempt to appear unique, everyone ends up doing the same thing.

Time and again it is said about people subscribing to various subcultures or styles: "they think they are unique but they all are the same!" However I have never once heard or seen anyone in any such group actually claim to be unique.

Indeed, what they (members of said sub-culture) all are is collectively different to, or in some way deviating too far from, whatever the current social norms, mores, or accepted majority cultural standards are. In this way, the group as a whole will appear unique compared to the majority of the population, who (usually) behave, dress and act in a (mostly) homogeneous way according to whatever the culture deems normal and within (somewhat) acceptable deviations.

I doubt that people posting these images are trying to be unique, they are chasing status.