What are the norms governing credibility assessments? How do we judge whether someone is telling the truth or not? What kind of good is credibility? Jennifer Lackey, Professor of Philosophy at Northwestern University, is interested in questions like these as well as testimonial injustice. Someone falls victim to testimonial injustice when he or she suffers a credibility deficit due to something about his or her identity. For instance, a woman calls the police because her husband is abusive. When the police arrive at the woman’s house, they disregard her complaint, writing it off as the woman being “overly emotional like all women”.
So what is it to get the credibility you deserve? The most common view is “to follow the evidence.” However, often times people are dealt a credibility deficit or a credibility surplus. A credibility deficit occurs when someone is not given due credibility and a credibility surplus occurs when someone is given an excess amount of credibility. Both can be moral wrongs. For instance, a male student is sitting in math class and struggling to understand a problem. Instead of asking his female neighbor for help, he waits until the next class to ask his male peer how to solve the problem. Provided that he did not ask his female neighbor to help because “she’s a girl,” this is an example of credibility deficit. A credibility surplus occurs if the male student had a question about baking cookies, for example, and automatically turned to his female neighbor, assuming that she would have extensive knowledge because “she’s a girl.”