Comment by Leftium

I suppose it would depend on the exact people and circumstances: the "social distance" can be very subjective.

- The same situation with different people or the same people in a different situation may result in different speech levels.

- If an older person feels really close to a junior, they may even ask them to "lower their speech."

There was a documentary about a much older Korean working for a very young boss. This resulted in a conflict: age hierarchy vs role hierarchy. They both spoke to each other in the formal style.

And think about addressing a mix of people who are both above and below you in the hierarchy...