Knowing other people's salaries gives you a stronger negotiating position. Other people knowing your salary gives you a weaker negotiating position.
Should you tell the world how much money you make? Are you altruistic?
Should you tell the world how much money you make? Are you altruistic?
So the question is what situation would someone think better serves their interests? Of course, whether one person describing their salary would evoke reciprocity or not is a question, whether another person would tell the truth is a question.
That being said - if an employee were to come to me and say "I want $X because so-and-so (or 'others on the team') are making that much", I would deny their request outright. That's a childish way to ask for a raise. It doesn't highlight what you're bringing to the team; only what you want to take from it.