The chapter starts with a description of data from population studies in Sweden from 2002 to 2020 regarding the extent to which there is trust in medical and social research, respectively, among lay people. Confidence in medical research is, on average, 30% higher than that in social research. Attitudes to research results are affected by wishful thinking. Results that are contrary to one’s preference are less likely to be accepted than those confirming preferences. Bribery (not necessarily monetary bribery) could be a problem in several stages of the scientific process. The concepts of confounders, positive bias, nihilistic bias, mass significance, and positive publication bias are introduced.