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Eyewitness testimony (EWT) is the evidence given by people who witnessed a crime or significant event, and it carries great weight in the justice system. Yet decades of research show that EWT is reconstructive and can be distorted by two main factors on the AQA specification: misleading information (leading questions and post-event discussion) and anxiety. Because mistaken eyewitness identification has contributed to real wrongful convictions, understanding these factors has high real-world importance.
Key Definition: Eyewitness testimony (EWT) is the account a witness gives of a crime or event, used as evidence. It depends on the accuracy of memory, which can be altered by misleading information received after the event and by the witness's emotional state at the time.
This lesson covers the AQA Paper 1 Memory content on factors affecting the accuracy of eyewitness testimony: misleading information (specifically leading questions and post-event discussion) and the effect of anxiety. You are required to know the relevant studies — Loftus and Palmer (1974) on leading questions, Gabbert et al. (2003) on post-event discussion/memory conformity, Johnson and Scott (1976) on weapon focus, Yuille and Cutshall (1986) and Christianson and Hübinette (1993) on real-life anxiety, and the Yerkes-Dodson inverted-U as a way of reconciling the conflicting anxiety findings. The topic builds on retrieval-failure theory (cues) and leads directly into the next lesson on the cognitive interview, which is the applied response to these problems. You should be able to describe the factors and studies (AO1), apply them to a witnessing scenario (AO2 where a stem is given), and evaluate the research and its implications for the justice system (AO3).
Misleading information is incorrect or suggestive information supplied to a witness after the event, which may alter their memory of it. It takes two forms on the specification: leading questions and post-event discussion.
Key Definition: A leading question is a question phrased so as to suggest a particular answer, or which contains an assumption that may influence the response. "How fast was the car going when it smashed into the other?" implies a violent, high-speed collision.
Aim: To test whether the verb used in a question about a car accident affects witnesses' estimates of speed.
Procedure: Forty-five American students watched several film clips of traffic accidents. After each clip they completed a questionnaire that included the critical question: "About how fast were the cars going when they ___ each other?" Five groups received a different critical verb: smashed, collided, bumped, hit or contacted.
Findings: The verb systematically affected the mean speed estimate. The most violent verb, "smashed", produced the highest estimate (around 40.8 mph), and the mildest, "contacted", produced the lowest (around 31.8 mph) — a difference of roughly 9 mph, despite all groups seeing the same clips.
Conclusion: A single word in a question can bias an eyewitness's report. This could reflect either response bias (the verb influences the answer without changing the memory) or genuine memory distortion — a question Experiment 2 was designed to address.
Aim: To test whether leading questions distort the actual memory or merely bias the response.
Procedure: A new sample of 150 students watched a film of a car accident. One group was asked the speed question with "smashed", a second with "hit", and a third (control) was not asked about speed. One week later, with no further viewing, all participants were asked: "Did you see any broken glass?" There was no broken glass in the film.
Findings:
| Condition | Reported seeing broken glass |
|---|---|
| "Smashed" | Highest (~32%) |
| "Hit" | Lower (~14%) |
| Control (no verb) | Lowest (~12%) |
Conclusion: Participants who had heard "smashed" were over twice as likely as the "hit" group to falsely remember broken glass a week later. Because the false detail appeared at a later test, this suggests the leading question altered the stored memory itself (Loftus's substitution / memory-replacement account), not merely the immediate response.
Loftus's wider programme showed the effect generalises beyond verbs. In one demonstration, witnesses asked whether they had seen "the broken headlight" (using the definite article, which presupposes a broken headlight existed) were more likely to report one than witnesses asked about "a broken headlight" — even when none was present. This shows that subtle presuppositions embedded in a question's grammar, not just emotive verbs, can mislead a witness.
Key Definition: Post-event discussion is the contamination of a witness's memory through discussing the event with other witnesses, or through exposure to other sources (e.g. media), after it has occurred.
Aim: To investigate whether witnesses who discuss an event incorporate into their own accounts details they did not actually see.
Procedure: Participants in pairs watched a video of the same crime (a woman stealing money), but each member of the pair had been filmed from a different angle, so each saw details the other could not. In the co-witness condition the pairs discussed the event before each completed an individual recall test; a control group recalled without any discussion.
Findings: A large proportion of the discussion group — about 71% — recalled at least one piece of information they had not seen themselves but had picked up from their co-witness. In the control (no-discussion) group, this did not occur (0%).
Conclusion: Witnesses' memories are distorted by memory conformity — they go along with, and absorb, information from other witnesses. This may stem from informational social influence (believing the other is right) or normative influence (wanting to agree), and it has clear implications: police should obtain statements from witnesses separately and promptly before they confer.
The effect of anxiety on EWT accuracy is genuinely contradictory: some studies show anxiety impairs memory, others show it enhances it. The two strands are usually reconciled with the Yerkes-Dodson law.
The Yerkes-Dodson law (1908) proposes an inverted-U relationship between physiological arousal (anxiety) and performance: too little arousal and the witness is under-alert; a moderate level produces optimal attention and recall; very high arousal overwhelms the witness and recall declines.
flowchart LR
LOW["Low anxiety<br/>under-aroused<br/>(poor recall)"] --> MOD["Moderate anxiety<br/>optimal arousal<br/>(BEST recall)"]
MOD --> HIGH["High anxiety<br/>over-aroused<br/>(poor recall)"]
On this view, whether anxiety helps or harms EWT depends on where on the curve the witness sits — which is why laboratory studies of extreme fear and real-life studies of moderate stress can reach opposite conclusions.
Aim: To test whether the presence of a weapon (raising anxiety) reduces accuracy of identification.
Procedure: Participants waiting for a study overheard a conversation in an adjacent room. In the low-anxiety condition a man then emerged holding a pen, with grease on his hands; in the high-anxiety condition a man emerged holding a blood-stained knife. Participants later tried to identify the man from a set of photographs.
Findings: Identification was less accurate in the knife (high-anxiety) condition (around 33% correct) than in the pen condition (around 49% correct).
Conclusion: Anxiety created by a weapon produces weapon focus — attention narrows onto the weapon at the expense of other details such as the culprit's face — reducing identification accuracy, consistent with high anxiety impairing EWT.
Aim: To investigate EWT accuracy in a real violent crime.
Procedure: Witnesses to an actual shooting in Vancouver (a shopkeeper shot a thief, who died) were interviewed by researchers several months after the event, and their accounts were compared with their original police statements. Witnesses also rated how stressed they had felt at the time.
Findings: Witnesses were remarkably accurate even months later, and resistant to misleading questions the researchers inserted. Those who reported the highest stress at the time were, if anything, the most accurate.
Conclusion: In a high-stakes, real-world event, high anxiety did not impair memory and may have enhanced it — directly contradicting the weapon-focus impairment finding and casting doubt on the generalisability of laboratory studies.
Interviewing 110 witnesses to real bank robberies in Sweden — some victims (directly threatened, very high anxiety) and some bystanders (less threatened) — Christianson and Hübinette found that witnesses recalled the events accurately, and that those who had been most directly threatened (the victims) showed the best recall, even after several months. This converges with Yuille and Cutshall: in real, life-threatening situations, high anxiety tends to be associated with better, not worse, memory.
It is not enough to show that misleading information distorts EWT; the specification rewards understanding of how it does so, and there are competing accounts. Distinguishing them is a key route to higher AO1 and AO3 marks.
| Explanation | Claim | What happens to the original memory? |
|---|---|---|
| Substitution / memory replacement (Loftus) | The misleading detail overwrites the original information | The original is altered or lost — the false detail replaces it |
| Response bias | The misleading detail affects only the answer given, not the memory | The original is intact; the witness simply reports what is expected |
| Source monitoring error | The witness confuses the source of the information | Both the true memory and the post-event information survive, but the witness mis-attributes the latter to the original event |
| Coexistence (McCloskey and Zaragoza) | The original and misleading versions coexist; the witness sometimes reports the wrong one | The original remains available alongside the false one |
The evidence does not settle cleanly on one account. Loftus and Palmer's delayed false-glass finding (a week later) is hard to explain by response bias alone and favours genuine memory change, supporting substitution. However, source-monitoring theory (Johnson and colleagues) offers an attractive middle position: rather than the original memory being destroyed, the witness fails to keep track of where each piece of information came from, mistakenly attributing the interviewer's leading phrasing or a co-witness's comment to their own perception of the event. This account elegantly explains both leading-question effects and post-event discussion (memory conformity), and it is consistent with findings that, under careful testing, traces of the original memory can sometimes still be recovered — which pure substitution would not predict. A balanced answer recognises that misleading information probably operates through more than one mechanism, and that the debate between destruction of the original memory and confusion about its source remains genuinely open.
A further refinement that helps reconcile the conflicting findings is the distinction between central and peripheral detail. Research suggests that the emotionally significant, central features of a witnessed event (for instance, the assailant's actions, or the weapon itself) are often well retained, and may even be sharpened by high arousal, whereas peripheral details (background information, the appearance of bystanders, surrounding objects) are more readily lost or distorted. This pattern — sometimes called tunnel memory — helps explain why real-crime witnesses (Yuille and Cutshall) can be highly accurate about the core of a terrifying event while laboratory weapon-focus studies find impaired memory for the peripheral detail of the culprit's face. It implies that the blanket question "does anxiety help or harm EWT?" is too crude: the answer depends on which kind of detail is being recalled.
A strength of the leading-question research is its experimental rigour. Loftus and Palmer used standardised film clips and a single manipulated word, holding everything else constant, which allowed them to attribute the difference in speed estimates and false memories directly to the critical verb. This matters because such control supports a confident causal conclusion — that the wording of a question, not some confound, distorts the report — and the studies are readily replicable. The implication is that the influence of leading questions on EWT rests on solid experimental evidence, which is precisely why the findings have been taken seriously enough to reform real interviewing practice.
Set against this, the artificiality of the research is a serious limitation. Watching a brief film clip of an accident is emotionally and motivationally quite unlike witnessing a real, sudden, frightening event in which one has a personal stake; participants know no real consequences follow, so they may attend, encode and report differently. This matters because it questions whether the laboratory distortions generalise to real witnesses, and indeed real-world studies (Yuille and Cutshall) found witnesses far more accurate and resistant to misleading information than the laboratory would predict. The implication is that Loftus and Palmer may overstate the fragility of real EWT — a caution reinforced by Foster et al.'s finding that participants who believed they were watching a real crime (whose testimony might matter) were less susceptible to misleading information than those who knew it was a study.
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