Sundar Pichai, chief executive officer of Google Michael Short | Bloomberg | Getty Images

Google's diversity program discourages debate on the topic of bias and encourages employees who participate in anti-bias training to keep details of the sessions secret, according to slides for leaders and participants of one such session used by the company. At least two of the slides back up some of the claims by fired engineer James Damore, who after attending such a session wrote a memo calling Google "an ideological echo chamber where some ideas are too sacred to be honestly discussed." The memo led to his firing and has ignited a nationwide firestorm over what he wrote and how Google management has responded. Many slides from the diversity training decks use real-world examples to explain how conversations can be unintentionally biased. One slide, for instance, suggests that an employee who tells another, "The interface needs to be so simple your mother can use it," is guilty of "stereotype bias."

Other slides, however, may explain why Damore thought Google "has created a politically correct monoculture that maintains its hold by shaming dissenters into silence." For instance, in a slide titled "Off-topic for this session," the first point underneath that heading reads: "Debating whether bias exists at your organization."

That suggests any argument that Google is not biased is unwelcome at the diversity sessions, which are voluntary. Another slide titled, "Create a safe learning space," includes this instruction: "Don't repeat what people said in this room."