As the joke goes: One: people who think there are two kinds of people, and Two: people who don't.
There are a myriad of kinds of people, but there are often strong dividing principals around a specific point that offer insight into choices, opinions, actions.
The classic example is that there are Lumpers and Splitters: those that habitually aggregate things (information, whatever) into piles, and label those collective piles.
Or people who see things as individual, unique elements that are distinct.
You can see the pros and cons of each. The efficiency (and inaccuracy) of Lumping. The time-consuming inefficiency (and greater accuracy) of splitting.
We all are Lumpers and Splitters in different areas of our lives.
We tend to be Splitters in areas of interest or importance to us, knowing and delighting in the myriad nuanced differences of a "thing," be it horror movies, romance novels or football. For many, the sentence, "I don't watch horror movies (any films)/read romance novels (books)/like football (sports)" dismisses the entire genre (or the entire medium, in a bigger Lump). Often accompanied by a dismissive, "They're all the same."
But to a fan, a Splitter, interest and knowledge in something transforms your world from black-and-white (yes/no) into a universe of color like in the movie The Wizard of Oz.
So for example, Lumpers might roll all scary movies into a ball of "horror" and make blanket statements about them.
But to a Splitter, there are many types of horror—per Steven King there are three: the gross-out; the unnatural; terror. But other Splitters parse it differently: supernatural/unnatural; slasher/splatter; disaster. All usually include elements of suspense, fear, mystery. And there is a truly infinite number of varieties on these themes with strong opinions and preferences for individual types.
As a fan of romances novels, I will keep myself under control, simply noting that three initial Splits could be contemporary, historical, fantasy. But each one of those then can be subdivided into suspense, paranormal, mystery, sexy, sweet, and so on. Again, with an infinite number of sub-genres, mixing and matching to please different palates.
Football—while seeming for some of us to be "all the same" (bunch of guys running up and down a patch of "turf" in matching outfits, trying to move an inanimate object in one direction or another)—in fact is also full of subtlety. You heard it here first! Coaches, owners, players, injuries, penalties, sanctions, criminal investigations, finances, fans and more all contribute an ever-shifting kaleidoscope of the game.
There are many circumstances where we simply have to Lump. We can't retain, effectively present or make decisions when we consider all the complexity of a large number of things. A business presentation starts with an "Executive Summary" offering in a single paragraph, the top-line conclusions of what may be a lengthy and nuanced piece of work.
We often judge others by a single action (perhaps cheating) and label and Lump the person a cheater.
But really, their action may have been specific, isolated in a particular situation, or an area they deem gray, (low level fudging on their expense report ) whereas other areas may be scrupulously black and white (the integrity of their work, their commitment to their job).
Lump it. Split it. But don't dump on either one....