Johanna Motzkau: To understand how we witness a crime we have to sort of also understand how memory more broadly works, and factors to bear in mind there are to do with that scientists divide this up into encoding.
That is when we witness something, the storage phase, which is the time that elapses between we’re witnessing and when we remember, and obviously the retrieval, which is when we remember or when we’re asked to remember something.
But then also what plays a role at all of these different, three different points in time is sort of personal and contextual factors, that is how we make sense of what’s happening.
And here it’s quite important to understand that memory is not what some people think it’s a bit like a video recorder or a tape recorder where certain information is just stored and recorded and it can then be retrieved one-to-one exactly as it happened, but we sort of remember within context and making sense of events, and I mean Elizabeth Loftus, a famous scientist in the area from America, she’s used the metaphor that says it’s a bit like pouring milk into tea.
So your memory’s the milk and you put that into your, sort of into your head, into the vessel that contains the memory but it diffuses to all sides. So once you want to retrieve it you have to make a lot of effort to reconstruct what went on.
And other scientists have gone a step further saying it’s not even possible to say that memory is like a vessel with something in it, but it’s more about a continuum of time going on and our experience continuously being involved in remembering and assuming and understanding what is going on.
So it’s I think quite useful to think of memory as a kind of three-step thing where it’s to do with the feelings we have towards an event, with the understanding we have of the event and then the sort of behaviours we’ve observed, our own as well as someone else's, and then you can see that kind of a lot of sense-making is going on.
And it’s not like a video camera, but we have to sort of make sense of the event, and a good example for that is the film Memento, where there’s a character who’s only got his short-term memory, so every five minutes or so he completely forgets what happened before, and he has to be completely reassemble what's gone on.
And he uses notes and Polaroid pictures and tattoos on his body to remember what’s gone on, and he makes notes on the Polaroids to explain who the people are he’s taken pictures of but still every time he looks at them again, that’s what the film shows quite impressively, it’s quite confusing because he can’t really make sense just of a picture and a note because every time he looks at it he reinterprets it differently.
So we can see it’s quite important that there’s some context and some understanding going on.
So when understanding how we witness a crime obviously we also have to take into account how someone understands a crime. So being at a crime scene there’s a lot more than just taking in details of what happens. So if you’re involved in a pub brawl or you’re present when a fight is going on, you might be under the influence of alcohol, there might be not very good lighting, so you might not be able to see very much.
You might have been looking in the other way, you might have been sort of really shocked and surprised because you didn’t know what was going on. You might also, because you’re not understanding what happens because you might not have seen how it started, you might sort of form wrong assumptions about who did what first, and that also flows into your memory. Finally, you might have been scared so the feelings come into it.
So on the one hand research has shown that if you’re really shocked and stressed by an event that might form a really precise memory of everything that’s gone on that’s called a flashbulb memory.
But on the other hand stress can also mean that you’re shut down completely and you disassociate from the event. So afterwards, apart from being very shocked, you can’t really remember anything. So this is in the sort of encoding stage when you’re witnessing lots of factors that can contribute to you having sort of gaps in your memory, which will obviously later on make it quite difficult to retrieve the full event.
Now during the time that passes between you witnessing and between the actual giving evidence about the event factors are sort of the length of time. Obviously if you’re not, if it’s long ago you might not be able to remember very well, but also the way we usually remember is also through telling other people. So the more often you’ve told someone else about it the better you might be able to remember.
But then also the more often you’ve told somebody else the more other factors might have influenced what you assumed has happened, and here the meaning-making comes in again because you might have told your mum, your mates, you might have told friends or someone in passing, and they might have asked you questions about the event, or you might have talked to someone who’s also been there.
We call this a sort of co-witnessing effect where people speak to be other persons that were present, and they form a collusive account of what went on, and again that’s not an unusual thing to happen because in everyday life this is exactly how we do remember.
And this also points to the fact that the way the legal system and the police want us to remember events are quite unusual actually. Because we don’t normally have to give very detailed accounts of everything that goes on, but it’s quite healthy to forget most of the things that you experience every day because you’d go mad if you were having to remember every single bit of it.
So suddenly you’re in a police station and you’re asked to remember all these various bits of an event, and that can be quite difficult and it’s very unusual. So you might inadvertently draw on things that you’ve talked about with other people. So you think well these three other people corroborated what I saw, and so that must be right, and I actually think I might have seen it as well, and so then the sources get sort of confused while you’re making sense of the events.
So you’re not quite sure have I seen this or have I heard it or has that person confirmed something I saw as well or was it just us making it up as we were talking together.
Also what plays quite a big role in remembering is sort of our own assumptions about how our memory works, as I said many people think or have a sort of impression that our memory is a bit like a tape recorder, so we assume our memory works fine because in everyday life it serves us fine, and also we very rarely get the occasion when our memory is proved wrong because we obviously don’t make tape recordings of everything we do, so we assume yeah I’m fine actually I remember all the important bits, which is also obviously because what we forget we don’t remember so we don’t have an account of all the huge amount of stuff you’ve forgotten.
But also that’s a very healthy thing to do because obviously you sort of own personality and who you think you are and how you operate in your life that sort of quite to a large extent you draw from your experience, which is maybe it’s your memory.
So trusting your own memory and your own accounts is a very important bit of being a healthy person, obviously, but in a legal context that’s not actually the case. So going into an interview or being a witness at court or talking to the police we might assume well my memory’s really good, I don’t forget important things.
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If you're interested in this area of study, there's a new postgraduate course from The Open University, Forensic psychology: witnesses, experts and evidence on trial