A False Memory of an Incident
September 25, 2018
by William P. Meyers

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People can lie without knowing it

I can see it perfectly clearly. A police officer is facing down a hall. A door swings open, to his right. To his left, sticking out from behind the door, is a machete. He grabs the wrist of the man he is searching for, causing the machete to drop. Then he arrests the man.

The only problem with this memory is a conflicting memory.

I was living in a run-down apartment building near Dupont Circle in Washington D.C. It must have been around late 1977 or early 1978. The phone rang. Doris (or whatever her name was), an old lady who lived across the hall, was terrified. I went to my door and looked out my peep hole. A man with a machete was banging on her door and yelling. I decided to trust her locked door for as long as it held. Soon he gave up and pounded on my door a few times. Then he was gone. Doris said she had already called the police. We agreed to wait for a while before going out.

Eventually I did go out. Down on the first floor the police were still around. I asked one what happened. He told me he had his gun out and intended to shoot the man if he was charged with a machete. Instead the man pushed open a fire door, and the police officer was able to grab his wrist and disarm him.

Clearly the memory of being in my room is the true one. Playing back the police story in my mind, and occasionally telling it to friends, created the second memory. No big deal for my memory, just move a couple of pieces around and it all seems real.

This is why witnesses are not always reliable.

This is why we write down agreements, so that if one person's memory is wrong, there is an external object to settle what the agreement was.

It is why courts prefer, or should prefer, physical evidence to eye witnesses.

That said, human memory is pretty good, for most of us, most of the time. It is because it generally works well that sometimes we make the mistake of thinking things happened exactly the way we remember them.

The flexibility of memory also explains a lot of lying. I learned early on that certain people, once they denied something had happened and made up a lie in its place, really remember the lie as if it had happened. I don’t like to mistrust people, but I do keep in mind that not all lies are purposeful. If someone has reconstructed their memory, or is repeating something they believe to be true, there is no way to detect the lie by their delivery. Only analysis and fact checking can set you right.