Theories of Forgetting | Psychology for UPSC Optional (Notes) PDF Download

Introduction

Forgetting is an everyday occurrence that affects our ability to recall information, from forgetting where we placed our keys to blanking on the name of someone we just met. But why does forgetting happen? Psychologists and neuroscientists have developed five theories of forgetting in an attempt to understand why our memories become hazy or vanish completely. These theories provide intriguing insights into the intricate nature of memory and shed light on the factors that contribute to forgetting. In this article, we will delve into each theory, examining its principles, supporting evidence, and real-life examples.

Theory 1: Displacement Theory of Forgetting

The displacement theory focuses on how forgetting occurs in short-term memory. Short-term memory has a limited capacity and can only hold a small amount of information, typically about seven items, at any given time. Once the memory reaches its capacity, new information replaces the old one. While there isn't a singular figurehead associated with this theory, numerous psychologists have conducted experiments and studies that support its principles. The displacement theory aligns well with the Multi-Store Model of Memory, illustrating that while some information enters long-term memory, other pieces of information in short-term memory simply fade away.

Serial Position Effect

The phenomenon of the Serial Position Effect supports the displacement theory. In experiments utilizing the free recall method, participants are asked to listen to a list of words and then attempt to remember them. Findings reveal that the first and last items on the list are the easiest to recall. The primacy effect explains why the first item is simple to remember, as it doesn't yet compete with subsequent items for a place in short-term memory. Conversely, the recency effect clarifies why participants remember the items at the end of the list, as they have not been displaced from short-term memory. However, the words in the middle of the list, pushed out by the last words, are less likely to be recalled.

Examples of Displacement Theory

To illustrate the displacement theory, consider a scenario where you've just learned a seven-digit phone number, and then you are presented with another number to memorize. Your short-term memory capacity is insufficient to retain both sets of information, resulting in the need to forget the first number in order to recall the new one. Another example is when you receive a grocery list from your partner before heading to the store. However, during your drive, much of the list slips away from memory, and upon arrival, you can only recall a few items.

Theory 2: 

Trace Decay Theory of Forgetting:

The trace decay theory was formulated by American psychologist Edward Thorndike in 1914, building upon the early memory work of Hermann Ebbinghaus. According to this theory, memories gradually fade over time if they are not accessed. When we learn something new, the brain undergoes neurochemical changes known as memory traces. Retrieving memories requires revisiting these traces formed during the encoding process. The trace decay theory suggests that the duration between learning and recalling a memory determines whether the information will be retained or forgotten. The shorter the time interval, the better the retention, and vice versa.

Serial Probe Task

Waugh and Norman conducted a "serial probe task" in 1965 to examine both the displacement theory and the trace decay theory. Participants listened to a long list of letters and later had to name the letter that came after a verbally presented letter. The results indicated that while the displacement theory could explain certain instances of forgetting, it did not account for all cases. Interestingly, when the list was read at a faster pace, participants performed better in the task.

Criticisms and the Need for Other Theories

The trace decay theory does not explain why individuals can vividly remember past events, even if they haven't consciously thought about them. Additionally, it fails to consider the influence of events occurring between learning and recalling the memory. To address these limitations, the interference theory of forgetting was developed.

Theory 3: 

Interference Theory of Forgetting:

The interference theory dominated the field of forgetting throughout the 20th century. It posits that memory recall can be disrupted by both previous learning and new information. Essentially, forgetting occurs because memories interfere with and disrupt one another. For example, by the end of the week, you might struggle to recall what you had for breakfast on Monday due to the influence of numerous similar meals consumed since then.

Early Interference Study

German psychologist John A. Bergstrom conducted the first study on interference in 1892. Participants were asked to sort two decks of word cards into separate piles. When the location of one pile changed, the first set of sorting rules interfered with learning the new rules, leading to slower sorting.

Proactive and Retroactive Interference

Interference can occur proactively or retroactively. Proactive interference arises when old memories hinder the formation of new ones, especially when the memories are similar or involve near-identical items. Retroactive interference, on the other hand, transpires when new memories alter or interfere with old ones. For instance, learning French after previously studying Spanish may lead to difficulties recalling the Spanish vocabulary due to the influence of the newly acquired French words.

Theory 4: 

Retrieval Failure Theory of Forgetting:

The retrieval failure theory, proposed by Canadian psychologist and cognitive neuroscientist Endel Tulving in 1974, suggests that forgetting often involves a failure in memory retrieval. While the information stored in long-term memory remains intact, the ability to retrieve it at a specific moment is hindered. The classic example of this theory is the "tip of the tongue" effect, where individuals struggle to recall a familiar name or word.

Encoding Failure and Retrieval Cues

Failure in memory retrieval can occur due to encoding failure or a lack of retrieval cues. Encoding failure prevents information from entering long-term memory in the first place, while retrieval cues act as triggers that facilitate memory recall. Relevant retrieval cues, such as semantic cues, state-dependent cues, and context-dependent cues, enhance the likelihood of retrieving information from long-term memory.

Theory 5: 

Consolidation Theory of Forgetting:

Unlike the previous theories that primarily focus on psychological aspects, the consolidation theory delves into the physiological processes underlying forgetting. Memory consolidation is a critical process that stabilizes memories and makes them less susceptible to disruption. It involves transferring memories from short-term memory to long-term storage, rendering them more resistant to forgetting. The term "consolidation" was coined by German psychologists Georg Elias Muller and Alfons Pilzecker in 1900, who also explained retroactive interference in terms of consolidation.

Other Theories of Forgetting

While these five theories of forgetting are frequently discussed in relation to memory and recall, there are other theories worth exploring. The motivated theory of forgetting suggests intentional or unintentional suppression of memories, often related to traumatic or shameful events. The Gestalt theory of forgetting posits that memories can be distorted or forgotten due to the brain's tendency to fill in missing information. While no single theory encompasses all instances of memory loss and recall, these additional theories provide valuable perspectives on the complex nature of forgetting.

Conclusion

Understanding the intricacies of memory and the factors contributing to forgetting is a captivating endeavor. The five theories of forgetting discussed in this article shed light on various aspects of memory recall and offer different perspectives on why forgetting occurs. While the true nature of forgetting remains elusive, these theories provide valuable insights and provoke thought-provoking discussions in the field of psychology. By exploring these theories, we deepen our understanding of memory and enhance our appreciation for the complexities of the human mind.