Eyewitness testimony: the reliability of memory, the effect of leading questions, post-event information, anxiety and weapon focus, the named contemporary study (Loftus and Palmer), the cognitive interview, and the types of long-term memory.

What this dot point is asking

Edexcel wants you to evaluate how reliable eyewitness testimony (EWT) is, explain the factors that distort it (leading questions, post-event information, anxiety and weapon focus), use the named contemporary study (Loftus and Palmer, 1974) as evidence, describe how the cognitive interview improves accuracy, and distinguish the types of long-term memory. This strand applies the reconstructive view of memory to a real-world problem: justice depends on whether witnesses can be believed.

The answer

The reliability of memory and reconstruction

Memory is not a video recording. At recall the brain reconstructs the event, filling gaps with schemas (expectations) and blending in any post-event information. This makes EWT vulnerable to distortion, which matters because juries find confident eyewitnesses persuasive even when they are wrong.

Leading questions and post-event information (Loftus and Palmer, the contemporary study)

In experiment 1, 45 participants watched films of car accidents and were asked how fast the cars were going when they hit / smashed / collided / bumped / contacted each other. Mean speed estimates rose with the violence of the verb: about $31.8$ mph for "hit" but $40.5$ mph for "smashed". In experiment 2, a week later, those who had heard "smashed" were more than twice as likely to report (falsely) seeing broken glass that was never in the film. Loftus and Palmer concluded that the leading question does not just bias the response but alters the stored memory through response bias and, more powerfully, substitution of post-event information into the original trace.

Anxiety and weapon focus

High anxiety can both impair and (sometimes) sharpen memory. The weapon-focus effect (Loftus, 1979) is the finding that when a weapon is present, witnesses fixate on it and remember the perpetrator's face less well, because attention narrows under threat (the Easterbrook hypothesis). However, real-world studies of genuinely traumatic crimes (Yuille and Cutshall, 1986) sometimes find accurate, durable memories, so anxiety's effect is not simple: moderate arousal may aid recall while extreme arousal impairs it (an inverted-U relationship).

The cognitive interview

• Report everything. Recall every detail however trivial; minor cues can trigger linked memories.
• Reinstate the context. Mentally return to the scene, including weather and emotional state, exploiting context-dependent and state-dependent retrieval.
• Change the order. Recall events in reverse, which reduces reliance on schemas and expectations and so cuts reconstructive error.
• Change the perspective. Describe the scene from someone else's viewpoint, disrupting schema-driven gap-filling.

Meta-analyses find the CI elicits about 35 per cent more correct information than a standard interview, with only a small rise in errors.

Types of long-term memory

Edexcel expects you to distinguish the types of long-term memory that the simple multi-store model could not explain:

• Episodic memory. Personal events and experiences, time-stamped (your last birthday). Declarative and consciously recalled.
• Semantic memory. General knowledge and facts (the capital of France), declarative but not tied to a time or place.
• Procedural memory. Skills and how to do things (riding a bike), non-declarative and largely unconscious, resistant to amnesia.

Evaluation (GRAVE)

• Generalisability. Lab EWT studies often use student samples watching films, so they may not generalise to real, emotionally charged crimes.
• Reliability. Loftus and Palmer's standardised lab procedure replicates consistently, giving high reliability.
• Application. The findings directly inform the cognitive interview and warn courts against leading questions, a strong real-world payoff.
• Validity. Filmed accidents lack ecological validity; the weapon-focus and post-event effects may be weaker in real life (Yuille and Cutshall), questioning external validity.
• Ethics. Studying real trauma raises ethical issues, so lab analogues are used, trading realism for participant protection.

Examples in context

Example 1. Post-event discussion between witnesses. When two witnesses to the same event discuss it before being interviewed, their accounts converge: each absorbs details the other mentions, even false ones (memory conformity). This is post-event information from a social source rather than a question, and it explains why police separate witnesses, mirroring the substitution effect Loftus and Palmer found with broken glass.

Example 2. Why the cognitive interview works on schemas. A witness to a robbery may "remember" the robber wearing a balaclava simply because that fits a robber schema. Changing the order (reverse recall) and changing the perspective both break the schema-driven narrative, forcing genuine retrieval rather than expectation-filling, which is why the cognitive interview raises correct details without greatly raising errors.

Try this

Q1. Explain what is meant by a leading question, using an example. [3 marks]

• Cue. A question phrased to suggest a particular answer; for example, asking how fast cars were going when they "smashed" (rather than "hit") raises speed estimates (Loftus and Palmer).

Q2. Describe the weapon-focus effect. [3 marks]

• Cue. When a weapon is present, the witness's attention narrows onto it, so they recall the perpetrator's face and other details less accurately (Loftus, 1979).

Q3. Distinguish between episodic, semantic and procedural long-term memory. [4 marks]

• Cue. Episodic = time-stamped personal events (declarative); semantic = general facts and knowledge (declarative); procedural = skills and how-to knowledge (non-declarative, largely unconscious).