In Chaos Monkeys, his memoir about his rocky career in high tech, Antonio García Martínez lists a few pithy rules for understanding how Silicon Valley really works. The best of these insider insights: “Company culture is what goes without saying.” That is, if you want really to understand the firms vying to invent the future, pay less attention to how they describe themselves than to the actions they take. Watch what they do, not what they say.

That lesson was driven home last week after the tech publication Gizmodo published a document that had been circulating privately among Google employees for about a month. The document describes a stifling climate of opinion: “Google’s left bias has created a politically correct monoculture that maintains its hold by shaming dissenters into silence.” The document asserts that this corporate conformity prevents open discussion of Google’s policies encouraging diversity, especially gender diversity.