How did the word basic come to be used as slang for "the majority" or "the conformed." Where was it's first usage as such a word? Is it a new internet frenzy or has this word been used as slang before?
Basic, is exactly that, basic. For example if you say a girl is a "basic chick" she's very ordinary, unoriginal, nothing special about her. The origin probably came from the real meaning of basic, but rappers started applying it to people. In this song by Kreayshawn, she talks about expensive handbags, and says she doesn't want them because it's basic. The reason it's basic is because just about any female with the money to buy those bags are walking around with them. http://www.youtube.com/watch?v=6WJFjXtHcy4 *mild language in the video
After Dictionary.com added this slang sense of "basic" to its dictionary database in 2015, lexicographer Jane Solomon, speaking in an interview with The Huffington Post, described their analysis of the sense:
We noticed that these new senses are being used exclusively as slang in casual contexts
These particular senses of basic started out as African-American slang. In this context, the adjective was originally used as a way to call someone out (usually a woman) on immature or obtuse behavior. As the term achieved widespread usage, people began to use it in reference to material displays (drinking pumpkin lattes, wearing Uggs, caring about brand names) that they believed to be indicative of shallow behavior.
That its use originated in African American culture helps answer the part of the question about where it came from. As for when, Green's Dictionary of Slang first cites the term in 2014, less than a year before this question was posted on EL&U. But there is significant evidence that the phrase was common in speech earlier than this in black culture, and only became popularized around 2014.
Most often used in reference to women, the phrase appears to have developed into its well-known slang form through the compound "basic bitch", as discussed in an article by Maggie Lange in The Cut.
The Basic Bitch: She exists in contrast to the Bad Bitch, the Boss Bitch, and the Dope Bitch. But who is she, really? The Basic Bitch has long been an ambiguous figure. Only recently has a clear definition of the Basic Bitch seemed to crystallize in the popular imagination. Last week, the success of a popular College Humor video relied on viewers’ recognition of the Basic Bitch as a distinct type: a terminally boring Sex and the City viewer and consumer of pumpkin-spice lattes.
Madeleine Davies, writing for Jezebel also in 2014, describes how the term became adopted from black culture into wider use, a trend which she describes as "ruining" the term.
But like with a lot of things that are supposedly new to the cultural consciousness, the "basic bitch" is really only new to one narrow part of our culture — white people. And just like with everything else that we've tried to take over (Brooklyn, jazz, any kind of martial art), we're ruining it.
The term "basic bitch" started to become commonplace in hip hop about 5 years ago; a short while later, Kreayshawn caught wind of it and then she was followed by other white people — the kind of white people who say stuff like "I'm sooooo basic right now" as they order at Starbucks...or the kind of white people who write for Jezebel and fall into a state of crisis as they consider their own basic-ness while drinking a smoothie on a gentrified New York street corner.
So if this source is to be trusted, it seems like this sense of "basic" developed in African American slang around the turn of the millenium, became "commonplace in hip hop" around 2009-2010, and grew in popularity when it was used by the rapper Kreayshawn in the song "Gucci Gucci" in 2012:
And we stunting like
Gucci Gucci, Louis Louis, Fendi Fendi, Prada
Basic bitches wear that shit so I don't even bother
The term developed into a full-blown slang phenomenon, complete with numerous analyses and write-ups, around 2014, not long before this question was first posted.