A still from a high-speed video of a 1985 Yamaha Maxim 700 motorcycle about to strike the side of a van with an articulated dummy rider.
Elizabeth F. Loftus and John C. Palmer did a study in 1974 that showed our memories can easily be altered by questions about an event that we’ve witnessed. They did experiments where subjects watched films of automobile accidents and then answered questions about what happened in the films. Her later studies focused on the inaccuracy of eyewitness accounts and the myth of "repressed" memories.
"…the way a question is asked can enormously influence the answer that is given. In this instance, the question, "About how fast were the cars going when they smashed into each other?" led to higher estimates of speed than the same question asked with the verb smashed replaced by hit. Furthermore, this seemingly small change had consequences for how questions are answered a week after the original event occurred."
The entire paper is available as a PDF file (the link opens the file) at the University of California at Irvine: "Reconstruction of Automobile Destruction: An Example of the Interaction Between Language and Memory">>