➡️ Bayes' Theorem + understanding new information

Hi! Welcome to the 36th edition of 💡learnshiv.

This newsletter is for thoughtful, ambitious professionals who recognize that career success and cultural literacy are increasingly inseparable. Every other week, I break down ideas that matter for modern life—from mental models to societal concepts—into actionable insights. Consider it your guide to working smarter and navigating complex systems with purpose.

Happy New year, friends! I took a month off of learnshiv, and am back with cool new frameworks, theories, concepts and more to help us thrive through the imperfect systems in which we live and work.

Today, we’re learning about Bayes’ Theorem. Wtf is it? Why does it matter in today’s climate of division and endless new information? How can you apply it at work or, in life?

Keep reading!

➡️ What is Bayes’ Theorem? (The Simple Version)

Bayes' Theorem, developed by Thomas Bayes in the 18th century, is a powerful framework for understanding how we should update our beliefs when presented with new evidence.

Imagine your brain has a built-in probability calculator. When you encounter new information, instead of immediately accepting or rejecting it, you adjust a mental dial. Bayes' Theorem is simply this: start with what you currently believe (your "prior"), then gradually adjust based on new evidence.

At its core, it teaches us that our beliefs aren't fixed (and shouldn’t be) – they're probabilities that should change as new information emerges. When you receive new information, your dial could go towards confirming what you already believe or move away from your current belief and towards something else.

➡️ Why does it matter?

We're living in an age where:

• Information comes at us 24/7

• Every side seems absolutely sure they're the right ones

• "Facts" often contradict each other and get interpreted in many different ways

• Social media rewards extreme viewpoints and the conflict they create

• It's harder than ever to know what's true and what information we should be referring to to make coherent decisions

Most of us respond to this chaos in one of three ways:

1. Dig deeper into what we already believe (intending to confirm it)

2. Feel overwhelmed and tune everything out (stop the flow of information)

3. Jump from one viewpoint to another (if your views can change that quickly, how strongly did you really feel about the first one?)

Bayes' Theorem (in my opinion) is a better approach: measured, thoughtful updating of our beliefs.

➡️ How to apply it (practical steps)

Work Scenario: Evaluating a Job Candidate

Starting point: "I think they might be good based on their resume"

Mental adjustments:

• First interview you can tell they're missing key skills (confidence decreases)

• Amazing references from trusted colleagues (confidence increases)

• They score highly on the assignment task (confidence increases more)

• Something feels off in the team interview (slight decrease)

• Final thought: "I feel pretty good about hiring them, but I should set clear expectations"

Daily Life: Trying a New Diet

Starting point: "My friends love this diet, so it probably works"

Mental adjustments:

• Scientific studies show mixed results (confidence drops)

• My doctor explains why it might work for me (confidence rises)

• First two weeks go okay (slight increase in confidence)

• Learn many people quit (slight decrease)

• Find a way to make it more manageable (confidence rises)

• Final thought: "Maybe I don’t have to implement this diet completely, but I can incorporate parts of it into my lifestyle"

Processing News: Understanding a Story

Starting point: "This headline seems believable"

Mental adjustments:

• Multiple reliable sources report similar facts (more confident)

• Original documents tell a different story (less confident)

• Experts on the topic disagree on meaning (much less confident)

• More facts emerge over time (slightly more confident)

• Final thought: "There's probably truth here, but it's more complex than initially reported"

➡️ Makes sense?

Instead of thinking in rigid terms ("This is 100% true" or "This is 100% false"), Bayes' Theorem encourages us to think in terms of:

• "I'm leaning toward believing this"

• "I'm becoming less sure about this"

• "I'm more convinced now"

• "I need more information"

It's like a mental dimmer switch rather than an on/off light switch. Your confidence in ideas can grow stronger or weaker as you learn more rather than jumping to absolute conclusions.

Remember: In a world of increasing complexity and division, the goal isn't to be perfectly correct – it's to be able to adjust your understanding when you’re presented with new evidence for or against your “prior.”

Our core values should be concrete, like “protecting the environment is important,” but our methods, strategies, and understanding of achieving these values should remain flexible and open to new evidence.

I hope that presenting Bayes’ Theorem will help you (as it helped me) realize that in a society like ours, where work feels like a race and the news cycle feels like a never-ending firehose, all we can do is listen, adjust, and keep learning.

Thanks for reading our 36th newsletter, I hope you liked it. Find me on Instagram or LinkedIn where I post even more little tidbits about learning and my life.

Have a great week, and stay curious,

Shiv 💁🏽‍♀️