Science Contradicts Popular Beliefs About Memory

A survey has found most Americans believe memory works in ways rejected by scientific consensus. The findings suggest juries and judges deciding disputes about memory need the help of expert testimony.

The peer-reviewed study is reported in Simons and Chabris, “What People Believe about How Memory Works: A Representative Survey of the U.S. Population.” The authors assert theirs is “the first large-scale, nationally representative survey designed to measure intuitive beliefs about the properties of memory.”

Two of the six beliefs about memory tested in the survey are particularly important in child sex abuse cases. In such cases a child’s account of being molested is often the only strong evidence a crime occurred. The reliability of the child’s memory can thus be the primary issue in the case.

Two survey questions asked, in essence, whether memory is as reliable as video recording and playback. The questions, known for short as “video memory” and “permanent memory,” asked whether respondents agreed or disagreed with these statements:

Human memory works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.

Once you have experienced an event and formed a memory of it, that memory does not change.

None of the memory scientists surveyed agreed with either statement. In the general population, though, 63% of people agreed, either “strongly” or “mostly,” with the “video memory” statement and 47% with the “permanent memory” statement.

According to the consensus of psychological science, human memory can be contaminated in any of its three stages: acquisition (observing or experiencing an event), storage (the passage of time after the event), and retrieval (reporting the event). Thus memory does not operate at all like a video camera and is not immutable.

Although misconceptions about memory found in the survey correlated with level of education, even among respondents with post-college education more than 40% agreed with these two statements.

The rules of evidence in most jurisdictions tell judges not to admit expert testimony at trial if they find the testimony would not be helpful to the trier of fact (the jury, in a jury trial). Often judges exclude psychologists’ testimony about memory by saying it merely confirms common sense and so would not be helpful to the trier of fact. This study shows otherwise.