As mentioned in earlier postings, credit and blame is at the heart of organizational psychology, for better or for worse. The "who, what, where, why, when, and how" of the assignment of positive regard or negative feedback in the workplace is a key driver of either productive or dysfunctional dynamics and performance at the individual, team, and organizational levels.
Here is a Credit and Blame 360 that assesses how fairly or unfairly a manager assigns credit and/or blame to his or her colleagues and subordinates:
Let's start with the first "item" on this 360:
"Assigns credit and blame based on facts and not personal biases"
It's a rare manager who is able to fully focus on facts without being unduly influenced by personal biases of all kinds, whether biases about people, situations, or the meaning of information about people or situations. In my experience, enlightened managers are aware of their personal biases, and work to correct them. For example, in assessing the performance of a subordinate, a mindful manager will consider how he or she would have assessed the quality, quantity or timeliness of the subordinate's work if it had been completed by someone else. This is analogous to the advice to "separate the person from the problem" provided by Fisher and Ury in their book "Getting to Yes".