Retroactive interference is forgetting caused by what you learn after: new information makes older memories harder to recall. Its mirror image is proactive interference, where old learning gets in the way of new. The effect was described by German psychologists Georg MΓΌller and Alfons Pilzecker around 1900 and became a core idea of interference theory; machine learning has its own version, called catastrophic forgetting.
Interference is strongest when old and new material share cues, as when two passwords, two languages or two procedures answer the same question.
02
Timing matters
Memories that have not had time to consolidate are more vulnerable; mental activity soon after learning can disrupt them even when it is not similar (Wixted, 2004).
03
Retroactive vs proactive
Retroactive: new learning blocks old recall. Proactive: old learning blocks new recall. Both are part of interference theory.
04
Stronger memories resist
Material that is rehearsed, tested and spaced over time is less easily overwritten.
Where you see it today
Catastrophic forgetting in AI
Neural networks show an extreme version of the effect: train them on a new task and performance on the old one can collapse (McCloskey and Cohen, 1989). Researchers at DeepMind proposed protecting the weights that matter for earlier tasks, an idea inspired by synaptic consolidation (Kirkpatrick et al., 2017).
Fine-tuning large language models
A study of continual instruction tuning found catastrophic forgetting across models from 1 billion to 7 billion parameters, covering domain knowledge, reasoning and reading comprehension (Luo et al., 2023). Companies that fine-tune a model on their own data face the same trade-off as a student cramming a second subject.
Retrieval practice and AI quizzes
Testing yourself on material produces better long-term retention than restudying it (Roediger and Karpicke, 2006). AI study tools that turn notes into quizzes put that finding into everyday use, as long as the quizzes come back to older material too.
Sleep as protection
In a word-pair experiment, people who slept after learning were more resistant to later interference than people who stayed awake (Ellenbogen et al., 2006). Learning something new right before a test, instead of sleeping, works against you.
Retroactive interference and related memory effects
Retroactive interference
What happensNew learning impairs recall of older memories
ExampleAfter a phone upgrade you cannot recall the old PIN
Proactive interference
What happensOld learning impairs recall of newer memories
ExampleYou keep typing last year's password
Catastrophic forgetting
What happensA neural network loses an old skill when trained on a new one
ExampleA fine-tuned model gets worse at tasks it used to handle
Misinformation effect
What happensInformation after an event changes how it is remembered
ExampleA leading question alters a witness's account
Testing effect
What happensRetrieving a memory makes it more durable
ExampleSelf-quizzing beats rereading
How to use it
Space out similar material: do not learn two near-identical procedures back to back.
Quiz yourself on older material after learning something new, not only on the new topic.
When a process changes, mark clearly what is different from the old one, so the cues stop competing.
Protect sleep after intensive learning, and avoid cramming new material right before a test.
When you fine-tune an AI model, test it on its old tasks as well as the new one before you ship it.
The Business Engineer lens
Every organisation that retrains people or models on a new process risks quietly losing the old capability. The Business Engineer view is that memory, human or machine, is an asset to manage: what you add can erase what you had unless you test for it.
It is forgetting caused by later learning: new information makes it harder to recall something you learned earlier, especially when the two are similar.
What is the difference between retroactive and proactive interference?
In retroactive interference new learning disrupts old memories; in proactive interference old learning disrupts the recall of new information.
How can you reduce retroactive interference?
Space similar material apart, test yourself on older material, highlight the differences between similar items and sleep after learning.
Does AI suffer from retroactive interference?
Neural networks show a version called catastrophic forgetting: training on a new task can erase performance on old ones, and fine-tuned language models show it too.
The complete explainer, cleaned up and reformatted for mobile.
Retroactive Interference is a memory phenomenon where new information disrupts the retrieval of older memories. It occurs due to competition for retrieval, interference strength, and cognitive load. This can impair memory recall and affect learning. Examples include language learning and sequential tasks. Understanding it is crucial for effective education and memory management.
FourWeekMBABusiness EngineerAt a glance
Retroactive Interference is a memory phenomenon where new information disrupts the retrieval of older memories.
Retroactive interference is most potent when the new information is acquired shortly after the original memory is formed.
Actively recalling previously learned information through retrieval practice can help combat retroactive interference.
Layout refreshed 7 October 2026. The article text below is unchanged.
Why it mattersFrom the article
Retroactive interference is a fundamental aspect of memory that has far-reaching implications in our daily lives, from language learning and education to information processing.
Understanding the characteristics and mechanisms of retroactive interference allows us to develop strategies to mitigate its effects and optimize memory retention.
Defining Retroactive Interference
Characteristics and Key Features
Retroactive interference is characterized by several key features:
Memory Impairment: The primary characteristic of retroactive interference is that it impairs the recall or retrieval of previously learned information. This can manifest as forgetting, confusion, or a reduced ability to access the original memory.
New Information: Retroactive interference occurs when newly acquired information interferes with the retrieval of older memories. The interference typically happens shortly after the new information is learned.
Similarity: The interfering information is often similar to the original memory in some way, such as sharing common elements, themes, or associations. The degree of similarity between the old and new information can impact the extent of interference.
Temporal Order: The timing of when the interfering information is learned matters. Retroactive interference is most potent when the new information is acquired shortly after the original memory is formed. The closer in time these events occur, the greater the interference.
Competing Memories: Retroactive interference implies a competition between the old and new memories when attempting to retrieve information. The interfering information competes for retrieval, making it harder to access the original memory.
Several cognitive mechanisms contribute to retroactive interference:
Interference Theory: Retroactive interference is consistent with the broader framework of interference theory. This theory posits that forgetting or memory impairment occurs when information competes for retrieval, and interference from new information can disrupt the retrieval of older memories.
Proactive vs. Retroactive Interference: Interference can be proactive or retroactive. Proactive interference occurs when previously learned information interferes with the acquisition or recall of new information. In contrast, retroactive interference occurs when newly acquired information disrupts the retrieval of older memories.
Similarity-Based Interference: The similarity between the old and new information plays a crucial role in retroactive interference. If the new information is highly similar to the original memory, it is more likely to interfere with retrieval. This is because the brain may struggle to differentiate between the two, leading to confusion.
Strength of Encoding: The strength with which memories are initially encoded can influence the susceptibility to retroactive interference. Memories that are encoded more strongly are generally more resistant to interference.
Temporal Gradient: The timing of the interference matters. Retroactive interference is most potent when the interfering information is learned shortly after the original memory is formed. As time passes, the interference tends to diminish.
Real-World Examples of Retroactive Interference
Retroactive interference is not just a theoretical concept; it has practical implications in various aspects of our lives:
Language Learning
Imagine trying to learn a new language while retaining your proficiency in your native language. The acquisition of new vocabulary and grammar rules can lead to retroactive interference, making it challenging to recall specific words or phrases in your native language.
Education
In an educational context, students often encounter retroactive interference when studying similar subjects or topics. For example, when learning about different historical events that occurred in a similar time period, the details of one event may interfere with the recall of details from another event.
Daily Information Processing
In our daily lives, we constantly encounter new information, from phone numbers and addresses to passwords and PINs. The introduction of new information can interfere with the retrieval of previously learned information, leading to memory lapses.
Mitigating the Effects of Retroactive Interference
While retroactive interference is a natural cognitive phenomenon, there are strategies individuals can employ to mitigate its effects:
Spaced Practice
Spacing out learning sessions over time can reduce retroactive interference. This is known as the spacing effect. By revisiting and reinforcing older memories before new information is introduced, individuals can strengthen the original memories.
Retrieval Practice
Actively recalling previously learned information through retrieval practice can help combat retroactive interference. Regular self-testing or quizzing on older material can reinforce memory retrieval pathways and make the original memories more resistant to interference.
Mnemonics and Organization
Using mnemonic devices and organizational strategies can aid memory retention. Mnemonics provide mental hooks that make it easier to retrieve information, reducing the likelihood of interference.
Prioritize Important Information
Recognize the importance of specific information or memories and prioritize them. By focusing on essential knowledge, individuals can allocate cognitive resources to protect those memories from interference.
Minimize Similarity
In situations where individuals are aware of potential interference, they can actively seek to minimize the similarity between old and new information. For example, when learning two similar concepts, emphasizing their differences can help prevent confusion.
Conclusion
Retroactive interference is a fundamental aspect of memory that has far-reaching implications in our daily lives, from language learning and education to information processing. Understanding the characteristics and mechanisms of retroactive interference allows us to develop strategies to mitigate its effects and optimize memory retention. By applying these strategies, individuals can harness the power of their memory while navigating a world filled with a constant influx of new information.
Learning Multiple Languages: When learning multiple languages simultaneously, the vocabulary and grammar of one language can interfere with the recall of words and phrases from another.
Studying Similar Subjects: When students study subjects with overlapping content, like biology and chemistry, information from one subject may interfere with the retention of details from the other.
Sequential Sports Skills: Athletes who need to master sequential movements, such as gymnasts or figure skaters, may experience interference if they switch to a new routine that disrupts their muscle memory for the previous one.
Remembering Phone Numbers: Trying to remember a new phone number can interfere with recalling the old one, especially if they are similar.
Textbook Reading: Reading multiple chapters from different textbooks in one study session can lead to interference, making it harder to remember specific details from each chapter.
Learning Musical Instruments: Musicians transitioning from one musical instrument to another may experience interference in terms of finger placement and muscle memory.
Computer Passwords: Frequent changes in computer passwords can lead to interference, causing users to mix up old and new passwords.
Navigation Routes: Trying to memorize a new route to a location can interfere with the ability to remember an old route to the same place.
Exam Preparation: Studying for multiple exams scheduled close together may result in interference, making it challenging to recall specific details for each subject.
Cooking Recipes: Learning and remembering new recipes can interfere with the retention of previously learned cooking techniques and ingredient combinations.
Key Highlights
Learning Multiple Languages: When learning multiple languages simultaneously, the vocabulary and grammar of one language can interfere with the recall of words and phrases from another.
Studying Similar Subjects: When students study subjects with overlapping content, like biology and chemistry, information from one subject may interfere with the retention of details from the other.
Sequential Sports Skills: Athletes who need to master sequential movements, such as gymnasts or figure skaters, may experience interference if they switch to a new routine that disrupts their muscle memory for the previous one.
Remembering Phone Numbers: Trying to remember a new phone number can interfere with recalling the old one, especially if they are similar.
Textbook Reading: Reading multiple chapters from different textbooks in one study session can lead to interference, making it harder to remember specific details from each chapter.
Learning Musical Instruments: Musicians transitioning from one musical instrument to another may experience interference in terms of finger placement and muscle memory.
Computer Passwords: Frequent changes in computer passwords can lead to interference, causing users to mix up old and new passwords.
Navigation Routes: Trying to memorize a new route to a location can interfere with the ability to remember an old route to the same place.
Exam Preparation: Studying for multiple exams scheduled close together may result in interference, making it challenging to recall specific details for each subject.
Cooking Recipes: Learning and remembering new recipes can interfere with the retention of previously learned cooking techniques and ingredient combinations.
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The concept of cognitive biases was introduced and popularized by the work of Amos Tversky and Daniel Kahneman in 1972. Biases are seen as systematic errors and flaws that make humans deviate from the standards of rationality, thus making us inept at making good decisions under uncertainty.
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The strategy attempts to remove traditionally formulaic and routine approaches to problem-solving by advocating creative thinking, therefore finding unconventional ways to solve a known problem. This sort of non-linear approach to problem-solving, can at times, create a big impact.
Bounded rationality is a concept attributed to Herbert Simon, an economist and political scientist interested in decision-making and how we make decisions in the real world. In fact, he believed that rather than optimizing (which was the mainstream view in the past decades) humans follow what he called satisficing.
The Dunning-Kruger effect describes a cognitive bias where people with low ability in a task overestimate their ability to perform that task well. Consumers or businesses that do not possess the requisite knowledge make bad decisions. Whatβs more, knowledge gaps prevent the person or business from seeing their mistakes.
Occamβs Razor states that one should not increase (beyond reason) the number of entities required to explain anything. All things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.
Antifragility was first coined as a term by author, and options trader Nassim Nicholas Taleb. Antifragility is a characteristic of systems that thrive as a result of stressors, volatility, and randomness. Therefore, Antifragile is the opposite of fragile. Where a fragile thing breaks up to volatility; a robust thing resists volatility. An antifragile thing gets stronger from volatility (provided the level of stressors and randomness doesn’t pass a certain threshold).
Systems thinking is a holistic means of investigating the factors and interactions that could contribute to a potential outcome. It is about thinking non-linearly, and understanding the second-order consequences of actions and input into the system.
Vertical thinking, on the other hand, is a problem-solving approach that favors a selective, analytical, structured, and sequential mindset. The focus of vertical thinking is to arrive at a reasoned, defined solution.
Maslowβs Hammer, otherwise known as the law of the instrument or the Einstellung effect, is a cognitive bias causing an over-reliance on a familiar tool. This can be expressed as the tendency to overuse a known tool (perhaps a hammer) to solve issues that might require a different tool. This problem is persistent in the business world where perhaps known tools or frameworks might be used in the wrong context (like business plans used as planning tools instead of only investors’ pitches).
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The Streisand Effect is a paradoxical phenomenon where the act of suppressing information to reduce visibility causes it to become more visible. In 2003, Streisand attempted to suppress aerial photographs of her Californian home by suing photographer Kenneth Adelman for an invasion of privacy. Adelman, who Streisand assumed was paparazzi, was instead taking photographs to document and study coastal erosion. In her quest for more privacy, Streisand’s efforts had the opposite effect.
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First-principles thinking β sometimes called reasoning from first principles β is used to reverse-engineer complex problems and encourage creativity. It involves breaking down problems into basic elements and reassembling them from the ground up. Elon Musk is among the strongest proponents of this way of thinking.
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Goodhartβs Law is named after British monetary policy theorist and economist Charles Goodhart. Speaking at a conference in Sydney in 1975, Goodhart said that βany observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.β Goodhartβs Law states that when a measure becomes a target, it ceases to be a good measure.
The Mandela effect is a phenomenon where a large group of people remembers an event differently from how it occurred. The Mandela effect was first described in relation to Fiona Broome, who believed that former South African President Nelson Mandela died in prison during the 1980s. While Mandela was released from prison in 1990 and died 23 years later, Broome remembered news coverage of his death in prison and even a speech from his widow. Of course, neither event occurred in reality. But Broome was later to discover that she was not the only one with the same recollection of events.
The bandwagon effect tells us that the more a belief or idea has been adopted by more people within a group, the more the individual adoption of that idea might increase within the same group. This is the psychological effect that leads to herd mentality. What in marketing can be associated with social proof.
Disruptive innovation as a term was first described by Clayton M. Christensen, an American academic and business consultant whom The Economist called βthe most influential management thinker of his time.β Disruptive innovation describes the process by which a product or service takes hold at the bottom of a market and eventually displaces established competitors, products, firms, or alliances.
Value migration was first described by author Adrian Slywotzky in his 1996 book Value Migration β How to Think Several Moves Ahead of the Competition. Value migration is the transferal of value-creating forces from outdated business models to something better able to satisfy consumer demands.
Groupthink occurs when well-intentioned individuals make non-optimal or irrational decisions based on a belief that dissent is impossible or on a motivation to conform. Groupthink occurs when members of a group reach a consensus without critical reasoning or evaluation of the alternatives and their consequences.
A stereotype is a fixed and over-generalized belief about a particular group or class of people. These beliefs are based on the false assumption that certain characteristics are common to every individual residing in that group. Many stereotypes have a long and sometimes controversial history and are a direct consequence of various political, social, or economic events. Stereotyping is the process of making assumptions about a person or group of people based on various attributes, including gender, race, religion, or physical traits.
Murphy’s Law states that if anything can go wrong, it will go wrong. Murphy’s Law was named after aerospace engineer Edward A. Murphy. During his time working at Edwards Air Force Base in 1949, Murphy cursed a technician who had improperly wired an electrical component and said, “If there is any way to do it wrong, he’ll find it.”
However, it was popularized in 1936 by American sociologist Robert K. Merton who looked at unexpected, unanticipated, and unintended consequences and their impact on society.
Fundamental attribution error is a bias people display when judging the behavior of others. The tendency is to over-emphasize personal characteristics and under-emphasize environmental and situational factors.
Outcome bias describes a tendency to evaluate a decision based on its outcome and not on the process by which the decision was reached. In other words, the quality of a decision is only determined once the outcome is known. Outcome bias occurs when a decision is based on the outcome of previous events without regard for how those events developed.
Hindsight bias is the tendency for people to perceive past events as more predictable than they actually were. The result of a presidential election, for example, seems more obvious when the winner is announced. The same can also be said for the avid sports fan who predicted the correct outcome of a match regardless of whether their team won or lost. Hindsight bias, therefore, is the tendency for an individual to convince themselves that they accurately predicted an event before it happened.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
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