vos Savant and the most controversial answer to the Monty Hall Problem – the story of a genius who changed our perception of probability

In September 1990, one woman changed the way mathematicians and millions of ordinary people think about possibilities and logic. Marilyn vos Savant, widely recognized as having the highest recorded IQ in human history, published an answer in Parade magazine that sparked discussions worldwide. It wasn’t an ordinary math problem—it was a battle between intuition and facts, between belief and evidence.

Who is Marilyn vos Savant? The IQ 228 Phenomenon

Before the world knew her because of the controversy, it’s worth getting to know vos Savant herself. Born in 1946, she was listed in the Guinness Book of World Records as the person with the highest measurable IQ, scoring 228. At just ten years old, she read all 24 volumes of the Encyclopaedia Britannica, memorizing most of the information contained within.

However, vos Savant’s genius did not directly lead her to financial success. Growing up, she faced financial difficulties and dropped out of university to support her family. This contrast—an underappreciated talent that ultimately gained worldwide recognition—sets the stage for her later achievements in the column Ask Marilyn, where she tackles the most complex puzzles of logic and mathematics.

The Monty Hall Problem: A Puzzle That Made the Scientific Community Think

To understand the controversy, you first need to know the puzzle itself. The Monty Hall problem, inspired by the famous game show Let’s Make a Deal, goes as follows:

Imagine you’re participating in a game show. You’re standing in front of three closed doors. Behind one door is a car—the main prize. Behind the other two are goats. You choose a door, say number one. The host, who knows exactly where the car is, opens one of the remaining doors, for example door three, revealing a goat.

Now you’re presented with a choice: stick with your original selection (door one) or switch to the remaining closed door (door two)?

The question that has fascinated mathematicians for decades is: what should you do to maximize your chances of winning the car?

vos Savant’s Shocking Answer: “Always switch”

When Marilyn vos Savant received this puzzle in her column, her answer was clear and decisive: “Yes, you should switch.” She explained that switching doors increases the chance of winning from one-third to two-thirds.

It sounds like something everyone could accept, right? Unfortunately, for millions of readers and scientists, vos Savant’s answer seemed completely wrong.

The Criticism Storm—When Scientists Attack

What followed her publication is described as one of the biggest attacks on a person with such a high IQ. Marilyn vos Savant received over ten thousand letters—many filled with outrage and mockery.

Particularly shocking was the reaction from the academic community. Nearly a thousand letters came from individuals holding PhDs in science. Among them, the dominant opinion was that vos Savant fundamentally misunderstood the concept of probability. Some wrote:

• “You completely failed your probability calculus”
• “This is the biggest mathematical mistake I’ve ever seen”
• “Maybe women just don’t understand math as well as men”

The last comment points to something beyond mathematics itself—gender biases that sought to delegitimize vos Savant’s answer not through scientific arguments, but through stereotypes.

Mathematics Wins Over Intuition: Why vos Savant Was Right

Despite immense pressure, Marilyn vos Savant did not back down. And she was right. Here’s the precise mathematical explanation:

Step one: Initial probability

When you make your first choice among three doors:

• The chance you’ve chosen the car is 1/3
• The chance you’ve chosen a goat is 2/3

This is absolutely key to understanding the entire puzzle.

Step two: The influence of the host’s knowledge

Now, the host opens one of the remaining doors and shows you a goat. This action is not random—the host knows exactly where the car is.

If your initial choice was a goat (which has a probability of 2/3), the host will always open the other door with a goat. If you switch to the remaining unopened door, you win the car.

If your initial choice was the car (probability 1/3), the host will open one of the two doors with a goat. If you switch, you lose.

Step three: The final conclusion

In summary: switching doors allows you to win in two out of three scenarios. This means the probability of winning when switching is exactly 2/3—precisely as vos Savant claimed.

How MythBusters and MIT Verified vos Savant’s Brilliant Answer

Although the mathematics supported vos Savant, external verification was needed to silence critics.

MIT conducted thousands of computer simulations of the Monty Hall problem. The results were unequivocal: the number of wins when switching doors consistently hovered around 2/3.

The popular educational show MythBusters tackled this problem physically and verified the results. Their tests showed exactly the same pattern, confirming vos Savant’s explanation.

Gradually, scientists and mathematicians who initially criticized her answer recognized errors in their reasoning. Many academic publications now explained why people struggle with this problem, and vos Savant was correct.

The Psychology of Change: Why Our Brains Are Deceived

If the mathematics was clear to vos Savant, the question remained: why was it so difficult for millions, including scientists?

The reason lies in how the human brain processes probability and change.

Probability assessment error: After the host opens a door, most people automatically assume the chance of the remaining unopened doors being correct is now 50/50. They forget the initial assumption that the chance of choosing the car in the first round was only 1/3.

Reset error: The brain treats opening the door as a new, unrelated event. In reality, the second choice is inherently linked to the first through the host’s knowledge.

Illusory simplicity: The fact that the problem involves only three doors makes it seem simple. This apparent simplicity masks the true complexity of conditional probabilities.

vos Savant’s Legacy: A Lesson in Logic, Courage, and Perseverance

The story of Marilyn vos Savant and the Monty Hall problem is more than just a mathematical anecdote. It’s a story of courage to stand by one’s beliefs in the face of overwhelming criticism. Although vos Savant had the highest recorded IQ, it was not intelligence alone that mattered—it was her willingness to step into the spotlight and face ridicule.

Her answer to the Monty Hall problem ultimately changed how probability is taught worldwide. Teachers now regularly use this example to show how intuition can deceive us and to teach students the importance of logical reasoning over impressions.

Marilyn vos Savant remains a symbol that truth matters more than popularity, and that logic always prevails over time—no matter how long it takes.