system
Given the following post, respond as if you're commenting on Reddit:
human
[TheCulture] there's a bit in Excession where a character almost vomits after seeing footage of torture. Why hasn't the Culture genofixed nausea out of existence?
gpt
The amount of modification a Culture citizen undergoes is a deeply personal thing.  Some citizens prefer to have almost nothing beyond baseline human, most will want genetic defects and human weaknesses alleviated as much as possible, and some choose to undergo full body modification to the extent that they don't even resemble a human anymore.  

The character in question has chosen to retain their reflex to vomit when exposed to extremely disturbing stimuli.  This is one of the more popular choices actually, there's a persistent fear that getting rid of responses like this takes away a little of what makes culture citizens human.