A recent paper surveys coverage of famous conclusions and examples in psychology that are the topic of active debate, or that are outright incorrect.
Perhaps the most famous case they discuss is the Kitty Genovese bystander effect example. This 1964 murder case was once considered a classic example of the bystander effect, people in groups not taking action because they assume someone else will or should take action. However, the truth turns out to be more complicated, with fewer witnesses than assumed, neglected calls to the police and some questionable journalism.
The paper documents inaccurate coverage of some of these topics in introductory textbooks, particularly media violence, stereotype threat and the bystander effect example. They discuss these inaccuracies in terms of the desires to support favored views (e.g., an ideological bias) or a preference for simplicity and conclusiveness which would present psychological progress in a positive light.
“Aside from this, textbooks had difficulty covering controversial areas of research carefully, often not noting scholarly debate or divergent evidence where it existed. .. The errors on these issues were universally in the direction of presenting controversial research or scientific urban legends as more consistent or factual than they are.”
Much of social science is inherently noisy and even the most reliable findings are usually multiply determined. The impatient response to that is to downplay what we don’t know, sweep complexity and uncertainly under the rug, and prematurely declare hypotheses to be established theories and established theories to be scientific laws.
Perhaps it would make for unsatisfying textbooks if we paid more attention to what we don’t know and instead discussed controversies in the literature. But one of the benefits that students could get from studying psychology is an accurate understanding of human behavior as complex and difficult to predict.