Mental Liquidity

I recently heard a phrase I love: Mental liquidity. It’s the ability to quickly abandon previous beliefs when the world changes or when you come across new information.

It shouldn’t be controversial. But mental liquidity is so rare. Changing your mind is hard because it’s easier to fool yourself into believing a falsehood than admit a mistake.

Albert Einstein hated the idea of quantum physics.

His own brand of physics was an extension of classic Newtonian physics, which viewed the universe as working in clean, rational, ways that could be measured with precision. Then quantum theory came along with the wild idea that some parts of the physical world could not be measured, because the very act of measuring a subatomic particle changed its movement. The best we could do when trying to measure parts of the world was to come up with probabilities and likelihoods.

That was practically heresy to Einstein, who let his quantum theory peers know how he felt.

“One cannot make a theory out of a lot of ‘maybes,’” he once told a group of physicists in 1927. God, he said, “does not play dice.”

Even when he remained professional about his misgivings, Einstein stood firm. “I admire to the highest degree the achievements of the younger generation of physicists that goes by the name quantum mechanics,” he once told an interviewer, “But I believe that the restriction to statistical laws will be a passing one.”

His peers were disappointed. “Einstein, I’m ashamed of you,” said quantum physicist Paul Ehrenfest, who felt the great physicist was being as stubborn as those who once doubted Einstein’s theory of relativity.

Within five years, a group of quantum physicists would win the Nobel Prize, solidifying their contributions and validating quantum theory.

Left unmentioned during the award ceremony was that the group was nominated by Einstein himself.

“I am convinced that this [quantum] theory undoubtedly contains a part of the ultimate truth,” he wrote in his nomination.

He had come around.

So much of what people call “conviction” is actually a willful disregard for facts that might change their minds. It’s dangerous because conviction feels like a good attribute, while its opposite – being wishy-washy – makes you feel and sound like an idiot.

There’s this thing in psychology called the end of history illusion, which is the idea that people are aware of how much their personality has changed in the past, but they assume it will be stable in the future. I laugh at who I was at age 20, but I assume that by age 60 I’ll roughly be the same person I am today. Part of the reason it occurs is because it’s too painful to accept that the beliefs I hold today might be wrong, temporary, or subjective.

Beliefs take effort and investment, and it hurts to realize that there may be limited ROI on your hard-fought convictions. For a lot of things in life – particularly politics, investing, and relationships – people don’t necessarily want the truth; they want certainty. Changing your mind is hard because it’s an admission that the certainty you once thought you held was an illusion. The path of least resistance is to cling to beliefs for dear life.

A question I love to ask people is, “What have you changed your mind about in the last decade?” I use “decade” because it pushes you into thinking about big things, not who you think will win the Super Bowl.

I am always so suspicious of people who say, “nothing.” They act like it’s a sign of intelligence – that their beliefs are so accurate that they couldn’t possibly need to change. But I think it’s the surest sign of ignorance and stubbornness.

Visa founder Dee Hock had a great saying: “A belief is not dangerous until it turns absolute.” That’s when you start ignoring information that might require you to update your beliefs. It might sound crazy, but I think a good rule of thumb is that your strongest convictions have the highest chance of being wrong or incomplete, if only because they are the hardest beliefs to challenge, update, and abandon when necessary.

Two critical things to keep in mind here:

Be careful what beliefs you let become part of your identity. Religion and politics are contentious because almost by definition your beliefs are part of your identity – you’re not just dealing with ideas and philosophies, but tribes and belonging. Another Dee Hock quote applies here: “We are built with an almost infinite capacity to believe things because the beliefs are advantageous for us to hold, rather than because they are even remotely related to the truth.” Things get dangerous when people let their investing and economic beliefs fall into the same category.

Most fields have lots of rules, theories, ideas, and hunches. But laws – things that are unimpeachable and cannot ever change – are extremely rare. Some fields only have a handful. A big problem arises when you try to force rules and theories to become laws. The few laws tend to be the most important things in any field. But everything else, like Einstein said, is just a theory of maybes.