How close can cat6 wires run next to each other?

[Chakravartin]

Crushing them together or bending them sharply may undo some of the benefits of twisted pair cabling. Running them side-by-side should be harmless.

https://en.wikipedia.org/wiki/Twisted_pair

Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs. It was invented by Alexander Graham Bell...