Bias in scientists themselves is discussed – is it in our DNA? I argue that it is; it had survival value early in our hominin history but is now a negative force. These cognitive biases must be acknowledged, understood in the context of our professional lives, and mitigated. Bias also operates within research teams, as groupthink, and this too must be managed. Confirmation bias is a dominant force but are we “lumpers or splitters.” How are data grouped or categorized, and how does “framing” influence our response to data, a total of 35 cognitive biases are described. Scientific fraud is rare and an entirely different problem but the impulse for it may share some of the same psychological roots.