I've read the book by Derek Freeman who argues that Margaret Mead's book "Coming of Age in Samoa" is based on misinformation and does not correctly represent adolescent sexuality in Samoa. Freeman says that Mead had only a short amount of time for her fieldwork so instead of doing a systemic study, she simply interviewed two of the Samoan girls that were accompanying her. But the girls did not take the interview seriously and told Mead exactly the opposite of their cultural customs.
The absolutely crazy part is that Mead never went further to confirm her findings and neither did her superior whom she was doing the research for. Her book has been used in anthropology, sociology and psychology courses since it has come out.
I think it's unbelievable that a pioneer of social sciences like Mead would form significant theories about culture and human behavior based on incorrect data and then allow this information to influence academics and students in her field. How could this happen?!