you can spot chatgpt output from across the room. it has a sound. that weirdly polished, slightly formal, aggressively organized tone that no human actually writes in.

why? it's not random. there are specific technical reasons.

the training data problem

language models learn from text on the internet. a huge chunk of that text is formal — wikipedia, news articles, academic papers, corporate blogs. the model absorbs this formality as "default good writing."

when you ask it to write something, it defaults to the style it saw most often in training. that style is informational, structured, and neutral. like a well-written wikipedia entry. technically correct. absolutely soulless.

the optimization problem

chatgpt was fine-tuned with reinforcement learning from human feedback (rlhf). human raters scored outputs, and the model learned to produce text that gets high scores.

what gets high scores? helpful, harmless, clear text. raters preferred organized responses with clear structure. so the model learned to always use headers, always provide balanced perspectives, always conclude neatly.

the result is text that's optimized for being rated as "good" by strangers, not for sounding like a real person wrote it. nobody talks like that. but it scores well.

the probability problem

language models generate one word at a time by picking the most probable next word. "the most probable next word" means the safest, most common choice. the word that fits best statistically.

humans don't write like this. we pick weird words sometimes. we start a sentence and change direction halfway through. we use a three-dollar word when a ten-cent word would work because it sounded better in our head. these "mistakes" are what make writing sound human.

ai makes zero mistakes. and that's the tell.

the patterns detectors catch

this is directly connected to detection. the robotic quality of ai text isn't just an aesthetic issue — it's a statistical signature.

low perplexity (predictable word choices), low burstiness (uniform sentence structure), overused transitions ("moreover," "furthermore," "it's worth noting") — these are measurable patterns that detectors flag.

what actually fixes it

prompting doesn't fix it at the model level. "write casually" makes the vocabulary slightly less formal but the underlying patterns stay.

what works is running the text through models that were fine-tuned on actual human-text corpora. paraai's paraphrase tool does this — it rewrites text using models that learned human patterns from real human writing. the output has natural variation, inconsistent rhythm, the kind of imperfect texture that makes writing feel real.

you can also fix it manually. read your ai draft out loud and edit everything that sounds wrong. but that takes forever. untraceable ai tools automate the hard part.