Tact is one thing, but if I were advising a younger person on this, it would be on cost/benefit of challenging and having a read for others' insecurity or openn

Tact is one thing, but if I were advising a younger person on this, it would be on cost/benefit of challenging and having a read for others' insecurity or openness. Even in older age, many have fragile egos and may throw their weight around to punish you just for the insolence of contradicting them. It's worth knowing what's at stake, what's the upside. It's not enough to be right. That applies not only to subverting authority, but also popular conventional wisdom, as beautifully exemplified in anecdotes from the book the Scout Mindset. If you're talking to those who value the pursuit of truth then not being a dick can be sufficiently disarming.