Why do we forget, and how reliable is memory, especially eyewitness testimony?
Explain theories of forgetting and the reconstructive nature of memory, including the reliability of eyewitness testimony with reference to Loftus
WACE Year 12 Psychology Unit 3: theories of forgetting (decay, interference, retrieval failure, motivated forgetting), the reconstructive nature of memory, and the reliability of eyewitness testimony with Loftus and Palmer's misinformation research.
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What this dot point is asking
SCSA asks you to explain the main theories of forgetting, explain what reconstructive memory means, and apply this to the reliability of eyewitness testimony using named research. The marked skill is linking memory distortion to real-world consequences such as wrongful convictions.
Theories of forgetting
Forgetting is the inability to retrieve information that was previously stored. Several theories explain it.
- Decay theory holds that memory traces fade over time if they are not used, especially in short-term memory. It struggles to explain why old memories can suddenly resurface.
- Interference theory holds that other memories disrupt retrieval. Proactive interference is when older memories disrupt new learning; retroactive interference is when new learning disrupts older memories.
- Retrieval failure holds that the information is stored but cannot be accessed without the right cue. The tip-of-the-tongue state and the effect of context-dependent and state-dependent cues support this.
- Motivated forgetting holds that we unconsciously block distressing memories (repression) or consciously avoid them (suppression).
The reconstructive nature of memory
Memory is not a video recording played back unchanged. Frederic Bartlett showed that we reconstruct memories each time we recall them, filling gaps using schemas (organised mental frameworks of expectations). This makes memory efficient but also vulnerable to distortion: details can be altered, added or lost, and we may feel confident in a memory that is partly false.
Eyewitness testimony and the misinformation effect
Because memory is reconstructive, post-event information can change what a witness reports. Elizabeth Loftus is the leading researcher on this.
In Loftus and Palmer's study, participants watched a video of a car accident and were asked how fast the cars were going when they hit, smashed, bumped, collided or contacted each other. Those asked with the word smashed gave higher speed estimates than those asked with hit. In a follow-up a week later, participants who had heard smashed were more likely to falsely report seeing broken glass that was never present.
This misinformation effect shows that the wording of a question can implant false details into memory. Loftus's wider work demonstrated that leading questions, suggestion and even entirely false events can be planted, which is why eyewitness testimony, despite seeming compelling, is often unreliable and has contributed to wrongful convictions.
Why this matters
Understanding forgetting and reconstructive memory informs the justice system (cautious use of eyewitness evidence, careful interviewing), education (the value of retrieval practice and good cues) and clinical practice (caution about recovered memories). It also explains why two honest people can remember the same event differently.