Mental Flexibility: Why Is It So Hard to Let Go of an Old Idea?

We say it about our parents, about our managers, and sometimes about ourselves.

And we usually sum it up in one word: stubbornness.

A father insists on standing in line to pay his bill in person, even though his daughter has shown him the app three times.

He isn’t stupid, and he doesn’t hate anything new.

He knows the old way, he trusts it, and it doesn’t make him feel like a beginner all over again.

The mind clings to what it’s used to.

The familiar doesn’t require thinking at every step, while the new takes effort and carries a bit of anxiety.

That’s why letting go of an old idea is often harder than hearing a new one.

Why? Because the old one has become part of your identity.

And the answer isn’t to change your mind every day. It’s something calmer than that: Mental flexibility, which means being able to hear an idea that’s different and new to you without feeling it as a personal threat.

What Is Mental Flexibility, Really?

In psychology, cognitive flexibility is considered one of three core executive functions of the brain, alongside inhibitory control and working memory, as researcher Adele Diamond explains in her well-known 2013 review.

It covers roughly three things:

• Shifting perspective: seeing a situation through someone else’s eyes.
• Thinking outside the box: finding a solution unlike anything you’ve tried before.
• Adapting: adjusting your plan quickly when circumstances change.

Notice that flexibility isn’t the absence of opinions.

A flexible person can hold strong convictions.

The difference is that they can set them aside for a few minutes and truly listen to someone else.

Why Does a New Idea Feel Like an Attack?

Because some of our ideas are no longer just information. They’ve become part of “who we are.”

In a study published in 2016 by Jonas Kaplan and colleagues, the researchers put forty people in a brain scanner and presented them with arguments that challenged their beliefs.

Some of these were political beliefs they held strongly, and some were ordinary beliefs with nothing to do with politics.

What did they find?

• Participants changed their ordinary opinions much more than their political ones.
• When their political beliefs were challenged, brain regions associated with thinking about the self became active.
• And those who resisted change the most showed higher activity in regions linked to emotion, such as the amygdala.

It’s a single study with a small sample, and brain scans don’t “read” thoughts.

But it fits what we all feel: when a new idea touches our identity, we don’t just discuss it… we defend ourselves.

Do We Become Less Flexible with Age?

There’s some truth in the saying we started with, but it isn’t the whole story.

In a review pooling 92 samples from studies that followed people over many years, Brent Roberts and colleagues found in 2006 that the trait of openness to experience rises in adolescence, then declines in old age.

So the pull toward the familiar really does grow as we age, especially in later life.

But is it destiny?

In a study published in 2012 by Joshua Jackson and colleagues, 183 people aged sixty to ninety-four took part in a sixteen-week training program in reasoning and pattern-solving, with weekly puzzles.

Compared with a group waiting for its turn, the participants’ openness to experience went up.

It’s one study, and the effect is moderate.

But it says something reassuring: age makes flexibility harder, not impossible.

And this matches what real life tells us: it’s not that our minds are literally slower, but that change takes effort, and the effort grows heavier the longer we’ve been set in our ways.

What Builds Flexibility, and What Doesn’t?

The good news is that flexibility can be built.

But not the way the ads promise.

In a comprehensive review of “brain-training” programs published in 2016 by Daniel Simons and colleagues, the researchers found strong evidence that people get better at the games they train on, and very weak evidence that this improvement carries over into everyday life.

In other words: a game on your phone won’t make you more open to your colleague’s opinion.

It seems that whatever you want to get better at, you have to practice that very thing.

An employee spent fifteen years on an old system at her company, and then a new system arrived.

Her colleagues complained for weeks, while she volunteered to learn it first.

It wasn’t easy, and she wasn’t smarter than them.

But she made the new system a daily exercise instead of seeing it as a threat.

The Common Misconception About Flexibility

Some people think a flexible person is someone who agrees with everyone, or who has no position at all.

That isn’t flexibility. It’s dissolving.

Flexibility means you listen, understand, examine, and then decide.

You might change your mind, or you might keep it while understanding it more deeply than before.

But someone who changes their mind with every person they talk to doesn’t have a flexible mind. They have a mind without roots.

A flexible branch bends with the wind, but the tree stays where it is.

How Do You Practice Flexibility?

1. Explain the opposing view at its best: Before you respond, put the other person’s view in words they would agree with. Example: “You think remote work weakens commitment because it’s harder to follow up, right?”
2. Separate the idea from your identity: Say “Right now, I think…” instead of “I’m the kind of person who…” Example: “Right now, I think this field doesn’t have many job opportunities.”
3. Shift perspective on purpose: Ask how someone else sees the issue. Example: How does your son see this decision? And how does your customer see it?
4. Try one small new thing every week: A different route, a dish you’ve never had, or a feature on your phone. Example: Ask your daughter to teach you one thing in the app you’ve been refusing to use.
   

A Simpler Mental Model

• The mind loves the familiar because it’s more comfortable, not because it’s more correct.
• An old idea is hard to let go of because it has become part of you.
• Flexibility means hearing something different without feeling threatened, not giving up your opinion.
• It may decline with age, but it’s built through practice in life itself, not in games.

The world really is getting more complex over time.

And complexity creates opportunities, but it takes a flexible mind to see them.

Whoever clings to old ideas without ever revisiting them may feel the world is an exhausting, draining place.

Not because the world is evil, but because their picture of it is out of date.

So ask yourself today: Am I protecting my identity? Or growing it?

And start with one step: in your next discussion, restate the other person’s view before you respond to it.

Further Reading

• Executive Functions — Adele Diamond, Annual Review of Psychology, 2013: The go-to review on executive functions, including cognitive flexibility.
• Neural correlates of maintaining one's political beliefs in the face of counterevidence — Kaplan, Gimbel & Harris, Scientific Reports, 2016: The study that tracked what happens in the brain when our strong beliefs are challenged.
• Patterns of mean-level change in personality traits across the life course — Roberts, Walton & Viechtbauer, Psychological Bulletin, 2006: How personality traits, including openness, change across the stages of life.
• Can an old dog learn (and want to experience) new tricks? — Jackson et al., Psychology and Aging, 2012: The experiment that raised openness to experience in older adults through training.
• Do "Brain-Training" Programs Work? — Simons et al., Psychological Science in the Public Interest, 2016: The review that explains why the benefits of brain games usually don’t carry over into everyday life.