Trapped Priors
I first started considering the concept of trapped priors after reading Scott Alexander’s eye-opening post on the subject. His exploration of how deeply-held beliefs resist change struck a chord with me and illuminated new perspectives on rational thinking. Alexander’s analysis paints a vivid picture of why some beliefs become unshakable, preventing us from adapting to new information and making more informed choices.
“The problem,” Alexander states, “is that once your priors get stuck, even mountains of contrary evidence might not be enough to dislodge them.”
This sums up the core issue: trapped priors can create a self-reinforcing loop that keeps beliefs intact, even when reality presents overwhelming proof to the contrary. In this post, I’ll try to work through how trapped priors affect rationality, highlight some real-life examples, and explore practical strategies for breaking free from their grip.
The Role of Priors in Perception and Belief Formation
To understand trapped priors, it’s important to first grasp what priors are and how they shape our cognition. A prior belief is an assumption or expectation that stems from past experiences. In Bayesian reasoning, these priors should ideally be updated as new evidence comes to light, allowing our beliefs to evolve and better align with reality.
Our brains weave together raw sensory data and prior knowledge to create a cohesive perception of the world. This integration is immensely useful because it enables us to process information efficiently. But as Alexander wisely points out,
“Perception isn’t just about what we see; it’s about what we expect to see.”
When priors become rigid, they warp our perception, leading to cognitive biases like confirmation bias and reinforcing existing beliefs.
An Example from Perception: The McGurk Effect
A striking example of how priors shape perception is the McGurk effect—an auditory illusion where visual cues influence what we hear. When the visual of someone saying “ga” is paired with the sound “ba,” the brain blends these conflicting signals, causing us to perceive “da.” This shows how our brain’s expectations can override raw sensory input.
While the McGurk effect might seem like a mere party trick, it underscores the strength of priors in dictating our interpretation of the world. When these priors harden into immovable beliefs, they can become trapped priors that hinder rational thought.
Trapped Priors and Confirmation Bias
Trapped priors play a starring role in confirmation bias—a cognitive distortion where we seek, interpret, and remember information that supports what we already believe. As Alexander notes,
“The more invested you are in a belief, the harder it is to let go, even when the evidence becomes impossible to ignore.”
This is how trapped priors fuel a cycle of selective attention and memory.
Consider someone who swears by a certain health supplement. Their belief, built on anecdotal evidence or biased research, solidifies over time. Even when credible studies reveal that the supplement has minimal effect, they may dismiss these findings and cling to supportive but less reliable data. This selective approach keeps the prior trapped, effectively shutting down rational reevaluation.
The Case of Phobias: How Fear Locks Priors
Phobias are a textbook example of how trapped priors can manifest in behavior. Take cynophobia, the fear of dogs. A single negative experience can set a strong prior that “all dogs are dangerous.” This belief can persist even after multiple encounters with gentle, friendly dogs. The mind filters out these neutral or positive experiences, reinforcing the initial fear.
Over time, this trapped prior cements itself, making it nearly impossible to adjust the belief without intentional intervention. Techniques like gradual exposure therapy work by introducing safe, controlled interactions that challenge the prior belief and help shift it toward a more balanced perspective.
The Implications for Rationality and Decision-Making
Trapped priors can severely limit rational decision-making. When we fail to update our beliefs despite new information, we risk making decisions based on outdated or false assumptions. This rigidity is particularly harmful in areas that demand flexibility, such as policymaking, medical decisions, and personal relationships.
Imagine a policymaker wedded to a specific economic model. If they ignore fresh data that suggests an alternative approach would be more effective, their decision-making becomes stagnant. Similarly, in relationships, holding onto entrenched beliefs about a partner’s behavior can block meaningful conversations and stunt growth.
Strategies to Overcome Trapped Priors
Breaking free from the hold of trapped priors is essential for fostering open-mindedness and adaptive thinking. Here are some actionable strategies:
Awareness and Reflection: Recognize that your current beliefs may be influenced by entrenched priors. Regularly challenge your assumptions and seek out differing opinions.
Incremental Exposure to Counterevidence: Just as exposure therapy can ease phobias, gradually introducing information that contradicts a prior can soften its grip. This method helps you re-evaluate your beliefs step by step.
Active Engagement with Contradictory Information: Instead of brushing off conflicting data, confront it head-on. Ask yourself why you’re resisting change and whether the new evidence has merit.
Feedback Loops: Build feedback mechanisms into your decision-making. Regularly assess whether outcomes align with your beliefs and be prepared to adjust accordingly. This is particularly valuable in professional settings with significant long-term implications.
Cognitive Training: Engage in practices that enhance cognitive flexibility, like mindfulness or cognitive-behavioral exercises, to help your mind stay open to new information.
Trapped priors are a formidable barrier to rationality. By understanding how these entrenched beliefs shape perception and decision-making, we can take active steps to keep our thinking flexible and responsive. Cultivating a mindset that values growth and adaptability can help us evolve our beliefs in line with new insights. Addressing trapped priors isn’t just an act of intellectual humility—it’s a necessity for better decision-making and personal development.