# Chapter 18: The Most Common Hoaxes in Genetics - Myths & Facts

Nowadays there is a lot of information available on the internet, and for the non-expert it is often difficult to find out which of them are true. Hoaxes or “fake news” are deceptive news items that appear to be true at first glance. There are several reasons why people tend to believe hoaxes. One is the nature of human thinking, which is subject to what is known as confirmation bias (the tendency to interpret and prioritise information that confirms our pre-existing beliefs) and conjunction fallacy (when two things happen at the same time, we consider it implausible that it could be a coincidence). Another reason why people believe hoaxes, is the lack of critical thinking and the inability to distinguish between correlation and causation (Figure 18.1). While correlation expresses that two phenomena have a certain relationship and happen at the same time, causality expresses that there is a causal relationship between these phenomena, that is, one phenomenon is the cause of the other. For example, if a person is clapping and it begins to snow at the very same time, these phenomena are correlated but not causally related. Similarly, the administration of an experimental drug to a patient and their recovery suggests a correlation between these phenomena. There could also be a causal relationship, i.e., that the administration of the potential drug caused the patient to be cured, but this needs to be proven by further investigation. However, the patient could also have been cured without the administration of the drug. It must be added that the causality of approved drugs has been confirmed by many years of research and numerous laboratory tests. In the rest of this chapter we deal with interesting and current hoaxes related to genetics.