> Many years later I heard an elderly man of whom I had a generally favorable opinion tell a child who had disagreed with him not to contradict his elders. I was shocked — the statement struck me as heresy, very nearly obscenity. If your elders are wrong, you have as much cause to contradict them as they would to contradict you if you were wrong.

Personally I would split this into two aspects: the tone that the argument is expressed in, and the meat of the argument. People who tell you not to contradict with elders (which I take to mean not just older relatives but also just people in a more senior position) usually only care about the tone of your voice, and the fact that your tone displays respect towards elders. And this is usually good advice: you want to avoid hurting their ego, because they are in a position of power and they can inflict harm and misery on you. On the other hand, once you speak in a sufficiently respectful tone these people don't really mind changing their mind in an argument. They don't like to be confronted and be forced to change their mind; they just like to feel respected while changing their mind. It's an art to speak in a way that protects the fragile ego of the counterparty while still contradicting them.