We can look at the credibility of a statement itself, but also at the credibility of the source from which a statement comes. It is important to know that credibility comes in gradations. Credibility is therefore not an all-or-nothing principle. Sources (often people) are not all equally credible. A person's credibility can also be reduced, for example when you hear that someone has a criminal record - or it can become larger because you hear that someone, for instance, has a master’s degree in neuropsychology.In general, the following can be said about a claim; a statement can be considered as unbelievable when the content of the statement is in contrast with was we already know (background knowledge), or if the source of the statement has an interest in whether or not you believe the statement.We therefore pay attention to these factors if we want to determine whether someone is credible. Unfortunately, we often base our judgment on characteristics that do not matter, such as age, gender, origin, accent, clothing and height. In fact, we should not base our judgment on someone's credibility on these factors. It is important to remember some rules of thumb when talking about credibility:"Interested parties" are less credible than other sourcesIf both the claim itself and the source (where the claim comes from) are not credible, then the claim must be distrusted. It is therefore important to consider two things: (1) the content of a statement itself and (2) where the statement comes from (the source).A statement is not very...