“Write like a human.” You mean write like a human writer? Because those are two completely different things. 

We have this false notion of human writing that’s characterized by colloquial verbiage, short sentences, and a conversational tone. It’s simple enough to not need parsing, so the cognitive load is low. It feels natural, taking the thinking out of the syntax and reserving it for the actual concepts being discussed. 

It’s meant to sound human. But does it read human?

The kind of writing that emulates everyday speech is a deliberate stylistic technique rather than the natural tendency that most people believe it is. 

Actual human writing trends toward:

• higher lexical sophistication (how advanced the vocabulary is),
• diversity (how varied the word choices are),
• density (how much meaning is conveyed relative to word count),
• along with more syntactic complexity (how elaborate sentence construction is). 

This is an empirical observation. We actually don’t write like we talk, and for good reason.

We naturally reach for bigger words and more complex construction when writing specifically because of what writing affords us. Unlike speech, where all the gears of cognition and expression turn in real time, text takes time out of the equation entirely. We can go back and make conscious decisions about the words we use, how we arrange them, and what kind of thinking even happens to enable those words. We can trade linguistic precision for conceptual breathing room.

The medium creates the opportunity, and we exploit that opportunity. 

There are a couple of things that motivate this decision: 

1. The performance of scholarship or professionalism, acquired over years of training. You want to sound like you know what you’re talking about. 
2. The atemporality of the written word. Spoken language happens in real time, with you doing the speaking.

You can adjust to feedback by softening your tone or clarifying your point. Your writing, on the other hand, travels across time and space. It may be attached to your name, but you’re not physically attached to it ready to defend your points on the fly.

You cannot parry. It must stand alone in your absence. So you over-index toward the resonance of authority and invulnerability. That decision influences your tone and word choice, a kind of preemptive strike against counterpoints by people reading your work. 

I’m not saying it’s right or wrong, but that’s how we do it. This is how writing is often found in the wild. 

So the next time someone sees your work — full of multi-syllabic words arranged in complex syntax — and tells you to write like a human, tell them that’s how humans actually write. They might be looking for something else.