Blog

 

Welcome to our blog! On this page, members of the Forensic Psychology Lab at The University of Sydney will write about current knowledge, theories, challenges, and issues in Forensic Psychology.  Our aim is to communicate scientific research to the general community to raise awareness about the importance of Psychology in the legal system . Enjoy!

 

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How does personality affect our memories of a crime?

By Lauren Monds: @LaurenMonds_AU

 

This post is about an article published in the Journal of Individual Differences: Doughty, Paterson, MacCann and Monds (2017). Personality and Memory Conformity. 

 

Following a crime, eyewitness testimony of the event is often relied upon to work out what happened. Unfortunately, we now know that eyewitness memory is not always an accurate record of what really happened. Besides spontaneous memory errors produced by the person, memory can also be influenced by others. This is known as the Misinformation Effect. One of the main ways that memory may be contaminated is through discussion of the event with another witness. This is known as ‘memory conformity’ or the ‘social contagion of memory’.

Importantly, people differ with regard to how susceptible they are to this influence from others; some people are highly susceptible to memory contamination while others are not. For example, in one study it was found that people with high levels of cognitive ability are better able to resist memory conformity compared to those with lower levels. This research is important in a court setting: jurors often rely heavily on eyewitness testimony to determine guilt or innocence. Therefore, we need to know which witnesses we can consider reliable, and which testimonies should be considered more carefully for accuracy. Based on this we conducted a study investigating the role of personality traits in memory conformity.

One of the predominant personality theories in psychology is the ‘Big Five’ model. Unsurprisingly, it divides personality into five main areas: openness, conscientiousness, extraversion, agreeableness, and neuroticism. Openness refers to an appreciation for new ideas and experiences; conscientiousness refers to the tendency to act with self-discipline and aim for achievement; extraversion is characterised by enjoyment and confidence in the company of others; agreeableness refers to the tendency to be cooperative and helpful; and neuroticism is characterised by high emotional reactivity and vulnerability to stress.

The aim of our study was to look at the Big 5 in relation to memory conformity.

Participants came into the lab and were given a personality test. They then watched a mock crime film where a thief gains access to an apartment, steals some items, and then is chased out by the occupant. After watching the film, participants discussed the crime with their co-witness – another participant who saw the same film. This is where it gets a bit sneaky though: the other participant is actually in on the whole experiment and they are there to purposefully plant false information about the film (this is known as a confederate). The confederate mentions correct information in the discussion as well as the false information so the true participant doesn’t become suspicious. After the discussion the real participant then is left to recall the event on their own. We then code this information to see if they report the false and true information introduced in the discussion alongside their own memories. For this study we then looked at how personality test scores were related to these memory scores.

So what did we find?

  • Openness: was related to greater resistance to memory conformity. This makes sense as previous research has found that openness is strongly related to intelligence/cognitive ability, and as we saw before cognitive ability is related to resistance of memory conformity.
  • Conscientiousness: fewer spontaneous, self-generated, errors. This also makes sense since conscientious people are achievement oriented and thus would be keen to avoid mistakes.
  • Extraversion: greater resistance to misinformation. It has been argued that extraverted people are more assertive and thus may be more likely to persist with their original version of events, which seems to fit our results.
  • Agreeableness: greater accuracy and fewer spontaneous errors. This finding requires a bit of speculation as we weren’t entirely sure why this might be the case. Perhaps it relates to the fact that they were more accurate specifically for the correct information provided by the confederate. So some conformity did occur; but while you might expect agreeable people to also accept the inaccurate information, this finding may mean that agreeable participants were focused on being cooperative and helpful to the overall goal of the study – accuracy for the event, rather than to cooperation with the other participant.
  • Neuroticism: Greater resistance and fewer spontaneous errors. Perhaps individuals in the current study were more self-conscious about the possibility of being seen as unreliable or inaccurate by the experimenter, than they were about being negatively evaluated by the co-witness.

So what can we do with this information? While it is useful to know how the different aspects of personality relate to memory conformity, people don’t just have one of the personality variables in isolation. They have a unique combination of all of them. For example, what if someone is highly agreeable and highly introverted? Further research is required into how these variables interact in an individual and how that relates to memory conformity.

Overall, these findings suggest that some individuals with particular personality characteristics may be more susceptible to accepting co-witness misinformation and reporting errors than others.

In the future this line of inquiry may have potentially important legal implications in terms of identifying individuals who are at risk of eyewitness testimony contamination and protecting these vulnerable witnesses from the potentially adverse effects of co-witness discussion.

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“If you have any information, please contact Crime Stoppers”: Can television crime re-enactments alter eyewitnesses’ memory of a crime?

By Hayley Cullen

 

Research has consistently shown  that information that eyewitnesses are exposed to after they witness a crime (known as “post-event information”) may alter their memory for that crime. Research on “the misinformation effect” has repeatedly shown for decades that inaccurate information presented after a crime occurs can be inadvertently incorporated into an eyewitness’ account of what happened. For example, in a classic study Loftus and Palmer (1974) asked participants questions about a video of a car accident and found that when the cars were phrased to have “smashed” into each other rather than “hit” each other, participants were more likely to falsely report seeing broken glass in the video. The majority of these studies focus on the negative effect that post-event information  can have on eyewitness memory.

 

However, post-event information is not always bad. As a matter of fact, it can actually strengthen an eyewitness’ memory if they are provided with correct information about the crime. Our lab co-ordinator, Dr Helen Paterson, and Associate Professor Richard Kemp (2006) have found that participants who are given correct information after a crime are more likely to report it compared to those who do not receive any information at all. Other recent research has found that eyewitnesses who are interviewed in pairs about a play they had seen a week before made fewer errors than an eyewitness who was interviewed by themselves, indicating that being able to discuss the event with one another allows eyewitnesses to correct each other’s errors (Vredeveldt, Groen, Ampt, & van Koppen, 2016).

 

This means that post-event information can have both positive and negative effects on an eyewitness’ memory. One type of post-event information that has never been studied is crime re-enactments. Thus, the question remains whether crime re-enactments have positive or negative effects on eyewitness memory.

 

Crime Stoppers, an Australian wide initiative, typically calls for members of the general public to assist with cases of unsolved crime. They broadcast crime re-enactments for the purpose of finding more eyewitnesses to provide details about a crime. In this way, crime re-enactments are considered to be useful and integral to the criminal investigation process. However, they are currently being used without knowledge of how they might influence an eyewitness’ memory of a crime. They may, in fact, contain correct information and thus strengthen eyewitnesses’ memory for the crime, but through use of actors to re-enact the crime, they may provide eyewitnesses with misinformation that could potentially alter their memory of what happened.

 

Under the supervision of Dr Helen Paterson and Dr Celine van Golde, my honours project was devoted to finding out how crime re-enactments may affect eyewitnesses’ ability to describe a crime they had seen and identify the correct perpetrator of the crime. One-hundred and thirty-five first year psychology students viewed different versions of a staged kidnapping at a bus stop. One week later, half of the participants viewed a re-enactment of the kidnapping, which warned participants that the people playing the child and the perpetrator were actors. All participants were then asked to answer open-ended questions describing what they had seen, and to select the perpetrator from a photo line-up that also contained the re-enactment perpetrator as a suspect. The results of our study showed that participants did accept misinformation from the crime re-enactment and this was evident in both their answers to the open-ended questions and their line-up selections. Participants who saw the re-enactment were more likely to report information that was inaccurately contained within the re-enactment, and were also more likely to select the actor from the re-enactment as the perpetrator of the crime. The correct information from the re-enactment did not appear to strengthen the participants’ original memory, and therefore it was concluded that the re-enactment did not posit any benefit for eyewitnesses.

 

The findings of our study shed new light on the effect that crime re-enactments have on eyewitness memory. While crime re-enactments are used because it is assumed that the information eyewitnesses come forward with will be accurate, this is not necessarily the case, especially if actors are being used and inaccurate information is being transmitted. Even a recurring warning about the use of actors is not enough to stop people from implicating an actor as a real culprit. Furthermore, as crime re-enactments are typically used for unsolved crimes (where the facts of the case may not be concretely established), there is always the possibility that the information used to create crime re-enactments is misleading and can therefore be inaccurately incorporated into an eyewitness’ memory. These findings suggest that we need to be cautious when creating crime re-enactments, and we should also be cautious about testimonies provided by eyewitnesses after viewing a crime re-enactment.

 

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The Problem with Inconsistency

Written by Misia Temler

 

In the legal system, we hear much about ‘consistency’ and ‘inconsistency’. For example, when we see headlines saying “DNA found was consistent with the defendant” we understand this to mean that lab tests concluded that DNA found at the crime scene matched that of the person on trial. When we hear that “witness testimony in court was inconsistent with the police statement”, we understand this to mean that the information the witness recalled in court did not match the information the witness recalled in the police statement. Inconsistent recall is often deemed discrepant and consequently unreliable or even deceptive. But is ‘inconsistent’ a term we should be using when discussing changes across memory recall?

 

In the dictionary, ‘inconsistent’ is defined as variant and also as conflicting, but are these two definitions the same when considering memory recall across retellings? Witnesses are often asked to repeat their personal account of what happened during the investigation and court proceedings. The expectation is for complete detailed recall that does not vary over retellings. Memory recall can be labelled inconsistent if omissions, additions, and especially contradictions are identified across memory reports (Barnier, Temler, & Sutton, 2014).

 

Detailed unchanging memory recall may not seem unreasonable based on most people’s experience with remembering. People expect to clearly remember important personal events.  The perception among many still is that memory works like a video camera, capturing our experiences simply by recording what is in front of us (Simons & Chabris, 2011). Personally relevant information can often be recalled vividly and this increases our confidence that the recalled details are correct. For example one may remember a birthday dinner celebration and recall details such as the smells from the kitchen, the music playing in the background, and the decor of the restaurant. Sometimes these autobiographical memories can be remembered so vividly that it feels like we are replaying our experiences. Yet, would these details remain the same across retellings?

 

Research tells us that, in actuality, autobiographical memory works very differently from a video camera. Rather than being a video recording, our memory is more like an artistic expression of reality. It originates from experiences but is influenced by strokes of interpretations where no two canvases are the same. We are guided by our senses – by what we see, hear, smell and touch, yet each memory is then also painted by our own personal schemas that shape and individualise each recollection. Our autobiographical memory accounts of events are continually updated.  Our personality, other similar experiences, motivation, emotion, and social influences contribute to changing our memory each time we remember (Barnier, Sutton, Harris, & Wilson 2008; Conway, Singer & Tagini, 2004; Harris, Paterson & Kemp, 2008).

 

Most of what we experience is, as a matter of fact, quite quickly forgotten. This is highly beneficial as recalling every single little detail would constrain our ability to draw, interpret or extract any meaning from the experience (Michaelian, 2011). The paradox is however that, although details are forgotten so that we may make sense of our experiences, elaborative recall remains important within the context of social remembering. Consequently, many details we forget are often filled in with new details to retain comprehensive narratives necessary for conversing and storytelling. These new details can be accurate or inaccurate. Complete narratives allow us more effectively to connect with others (Fivush, Habermas, Waters, & Zaman, 2011).

 

In my own PhD research on autobiographical memory variability, I found that when participants recalled their memories of important personal past events, such as a birthday celebration or first date, over two retellings just one week apart, they all made omissions, additions and many made contradictions.  Although their memory reports changed, the amount recalled remained constant. When the changes were pointed out, participants recognised that their memory reports varied but maintained they were not conflicting (Temler, 2015).

 

Most people do not realise that they misremember. In our normal social settings, we discuss our memories with friends and acquaintances and minute details are rarely challenged. We often provide detail to support the coherence of our narratives. It may be to teach, entertain, socially bond, or express what the event meant to us. Yet in a forensic setting, variance in details can have serious consequences. Personal recollections are transcribed and scrutinized.  Omissions, additions and contradictions are referred to as inconsistencies and the credibility of the reports and witnesses can be compromised.

 

The confusing interpretation of  ‘inconsistency’ can lead to complications in the forensic setting. It is important to recognise that autobiographical memory reports across retellings will always be variant due to the reconstructive nature of autobiographical memory, but this does not always mean they are conflicting. Perhaps, rather than referring to memory reports as simply ‘consistent’ or ‘inconsistent,’ a distinction should be drawn between variant and conflicting.

 

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False memories for a distressing event: The role of cortisol

Written by Lauren Monds

This post is about an article published from our lab in the journal Memory.

 

One of the main themes from my PhD research involved looking at susceptibility to false memories after viewing a stressful or neutral film. One of the common techniques used by our lab to study trauma is the trauma film paradigm. This allows us to investigate what key characteristics or vulnerabilities people might have prior to a traumatic event and use them to predict how they will respond to the film.

One of the predictive variables I was interested in looking at was the hormone cortisol, which gets released into the body when a person is stressed. One of my main hypotheses was that since excessive cortisol levels can potentially impair memories, if people are more stressed and release more cortisol they might have worse memories for some aspects of the film. This may make them more likely to accept false information about the film into their memories, which I implanted through a fake eyewitness account of the event.

So how do you measure cortisol levels? There are two main ways: blood and saliva. There is one potential problem with using blood sampling for stress analyses – many people find venepuncture (taking blood through a needle into your vein) distressing. So this would be a potential confound. So I decided to collect saliva samples to run analyses to look for differences in cortisol levels. Collecting spit IS as unpleasant as it sounds. Participants spit down straws into tubes, and then the samples get stored in a fridge until they can be frozen for later analysis.

saliva

saliva collection supplies from here

Importantly, in Australia, saliva is considered a BIOHAZARD. This means that many extra precautions need to be considered when collecting and analysing bodily fluids. So, before you’re allowed to open up the tubes of saliva to analyse, they have to be irradiated (by using the cobalt cave).

saliva2

Not my actual samples, but it kind of looks like this [via].

For this particular study, participants came into the lab, completed several psychological measures and provided a baseline cortisol sample. They then watched either a neutral or distressing film and received an ‘eyewitness statement’ to read which contained several misleading details. Participants also completed measures of distress and provided additional cortisol samples after the film.

It took over a year to collect data for this study due to slow recruitment. For some reason watching a distressing film and spitting into a tube does not seem to be a popular experiment to volunteer for!

Finally, we got there in the end. We found that a greater cortisol response was observed in those participants who viewed the trauma film in comparison to the neutral film. However, not everyone responds to distress with an increase in cortisol, so people were split into cortisol responders and non-responders. Cortisol responders had on average a 40% increase in cortisol levels after viewing the trauma film. Interestingly, cortisol responder status was related to greater susceptibility to false recall. This led us to tentatively conclude that following a stressor, the individual responder may differ with regard to whether they experience a stress-induced cortisol increase. This may in turn affect whether they remember an upsetting event accurately. As this was an analogue study (i.e., using a film rather than studying an actual traumatic event), it is important to conduct similar research in a clinical population. To be able to pinpoint which people experience these phenomena may be helpful in determining which people make credible eyewitnesses, and which people to monitor for development of a more severe trauma response, such as PTSD.

 

 

Citation: Monds, L.A., Paterson, H.M., Ali, S., Kemp, R., Bryant, R., McGregor, I.S. (2015). Cortisol response and psychological distress predict susceptibility to false memories for a trauma film. Memory.

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Lie to me.

Written by Lauren Monds

 

Actually, please don’t because unfortunately, lie detection isn’t always as easy as it is made out to be on TV and in the movies. Some lie-detection methods are not overly reliable; as such many are not admissible in court proceedings. However, there is some exciting lie-detection research that is very promising.

 [picture via]

Lying to someone involves several cognitive processes, all operating at once. This is because not only do you need to keep your ‘story’ in working memory to make sure it stays consistent, you have to monitor your body language and voice pitch to make sure you’re not giving off signs that you’re lying (e.g. What’s the appropriate level of eye contact? Is my voice shaky? I should try not to look nervous… etc.). Additionally, you need to constantly monitor the person you’re lying to, to make sure they believe you. So Prof. Aldert Vrij and others have been working on making police interviews more cognitively demanding, so that verbal and non-verbal cues of deception are more likely to leak out, due to the liars having fewer resources to cope with the demanding nature of the interview.

A few lie detection ‘tips’:

  • People ‘know’ that liars avoid eye contact. However, this may not be true; since this is so commonly known, liars may try to keep eye contact to make sure it doesn’t look like they’re lying (and so they can check you’re believing them).
  • Another thing people ‘know’: liars fidget. Again because people are aware of this, sometimes liars may instead be trying very hard to control all their body movements and appear very rigid. Additionally, fidgeting usually indicates nervousness. What if the liar just isn’t nervous?
  • Some people think liars will have more speech errors: “umm, ahh” etc. However in some cases, rehearsed stories may come out smoother, without these errors.

As you can see, these tips aren’t overly helpful, because people react in different ways. All that has really been demonstrated is that looking for common signs of lying are probably somewhat pointless, if the liars know those signs too. So they may look at you, or look away. They may fidget, or be perfectly still. In many cases, if you’re in a situation where you’re accusing someone of lying, a truth teller is still probably going to be nervous, and just as interested in making sure you think they’re telling the truth. So this means they could act in very similar ways to a liar!

There are actually helpful indicators of lying out there, but I’m not going to tell you them, sorry! It’s important that police are still able to have the upper hand in interviews so that they can catch criminals!

Further study: Research suggests a very small proportion of people may in fact be ‘Truth Wizards’ that are able to detect subtle microexpressions and pick out liars.  In fact, this blog: Eyes for Lies, apparently belongs to one of the people who has been identified as a truth wizard, and claims to have a 96.9% accuracy rate in lie and truth detection. She gives her take on some high profile cases. Worth checking out.