It's only partially true. There's a reason people hide their cards in competitive games (like poker or bell curve-fitted tests) – it can put you a higher relati

It's only partially true. There's a reason people hide their cards in competitive games (like poker or bell curve-fitted tests) – it can put you a higher relative rating. However, humans are complex and if you have a trust codex like "i am open to sharing openly only with others who respect this codex", it'll benefit the participants – iff the game is non-zero sum and has repeated interactions (such as most careers, especially in creative professions). Such a meta-game is more fragile (trust can be eroded quickly), but can benefit everyone in an absolute sense. This game theoretical fundamental truth can be found in animals with symbiotic relationships, as well as codified in moral frameworks (eg the Christian golden rule). Search for "evolution of trust" if you want to see interactively how it plays out, it's fascinating and highly applicable to social behavior and cultures.