What is Necessary to Avoid Becoming a 'Toxic Senior': How a Fixed Mindset Kills Organizations

I do not dislike the feeling of melancholy.
In fact, I even like it.
By reflecting on old scenery, past successes, and the passion of those days, I can return to my origins, and there is a certain richness in that.
However, if one immerses themselves too deeply in melancholy, they become a resident of the past without realizing it.
And when they do realize it, they have become what is called a 'toxic senior' (rogai).
This is not a problem of age.
It is a problem of mindset.
In this blog, I would like to define the concept of 'toxic senior' head-on, dissect why it happens using data and psychology, and then develop a practical theory for avoiding that trap with the spirit of Ranko Koshin.

What is Ranko Koshin? — The Decisive Difference from 'Onko Chishin'

The source of Ranko Koshin is the biographical section of the Chinese official history, the 'Book of Han' (Hanshu).
This term, read as 'viewing the old and examining the new,' is characterized by the fact that it goes beyond simply looking back at the past to taking the proactive step of 'examining' new problems from it.

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Ranko Koshin vs. Onko Chishin Comparison
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　　　　　　　Ranko Koshin　　　　　　　Onko Chishin
Source　　　　'Book of Han' Biography　　　'Analects' Weizheng
Direction　　　View old → Examine new　Learn old → Know new
Nuance　　　　Active examination/Action-oriented　Passive learning/Accumulation-oriented
Synonyms　　　Inheriting the past/Opening the future　Ranko Koshin/Immutable and changing
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While Onko Chishin is closer to a stance of acceptance, meaning 'learning principles from old things,' Ranko Koshin places weight on a stance of action, meaning 'actively thinking up new things after having thoroughly viewed the old.'
This difference may seem small, but it is significant.
It is the difference between treating the past as 'reference material' or as a 'starting point for thought.'
I believe that immersing oneself in melancholy means treating the past as a 'conclusion.'
That is where thinking stops.
Ranko Koshin is a term that sets that stopped thinking in motion again.

The True Nature of the 'Toxic Senior' — Reading the Discrepancy Between Dictionary Definitions and Reality with Data

The term 'toxic senior' (rogai) is defined in dictionaries as 'a state in which central figures in companies or political parties continue to hold real power even as they age, and no rejuvenation is taking place' (Digital Daijisen).
Its first literary appearance was in a passage from Seicho Matsumoto's long political novel 'Meiso Chizu' (Stray Map), published in 1982.
Since then, it spread rapidly on the internet from the early 1990s to the 2000s, and today it is used widely from organizational theory to everyday language.

However, the way the term 'toxic senior' is used today is not limited to organizational talk.
The Seisenban Nihon Kokugo Daijiten explains it as 'harm caused by old age. A term used to criticize the aging of people at the center of companies or politics, implying the need for rejuvenation,' but in reality, there are many points being made that 'toxic senior behavior can also be seen in people in their 30s and 40s who can only see the past.'

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5 Major Characteristics of a 'Toxic Senior' (Integrated from multiple surveys)
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① Never change their own opinion (groundless confidence, overestimation)
② Low boiling point and easily emotional (venting anger even in public spaces)
③ Forcing their own values on others (habit of saying 'it was like this in the old days')
④ Long-winded and repetitive (repeating past success stories)
⑤ Claiming to be an old person depending on the situation (conveniently switching between power and victimhood)
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* Age irrelevant: Terms like 'young toxic senior' and 'soft toxic senior' exist for those in their 30s and 40s

What is important here is that the essence is not 'age' but 'rigidity of thought.'
Being a toxic senior is not a problem of aging, but a problem of thinking that has stopped updating.
This can happen in one's 40s, or even in one's 30s if taken to the extreme.
If there is a correlation between age and becoming a toxic senior, it is merely because there is a psychological tendency for the 'amount of past success stories' to increase with age, making it easier to become fixated on them.

Japan's Toxic Senior Risk Shown by Numbers — The Shock of the Average Age of Presidents Reaching a Record High for 34 Consecutive Years

To grasp the problem structurally, let's look at data on the age of executives in Japanese companies.
According to the 'National President Age Analysis Survey' conducted annually by Teikoku Databank, the average age of presidents nationwide as of 2024 is 60.7, continuing to hit a record high for 34 consecutive years since 1990.
The president turnover rate is a mere 3.75%, declining for 4 consecutive years.

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Japanese President Age Data (Teikoku Databank 2024 Survey)
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Average age of presidents　　　　: 60.7 (Record high for 34 consecutive years)
President turnover rate　　　　　: 3.75% (Declining for 4 consecutive years)
Percentage 50 or older　　　　: 81.7%
Percentage 60 or older　　　　: 51.7% (Over half)
Percentage under 30　　　　　: 0.2%
Percentage in their 30s　　　　: 2.9%
Average age at president turnover: 68.7 (Level approaching 70)
Average age at new president inauguration: 52.5
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Source: Teikoku Databank 'National President Age Analysis Survey (2024)'

Furthermore, according to a survey by Tokyo Shoko Research (February 2025), the average age of presidents in 2024 was 63.59, which is also a record high.
In addition, the correlation between president age and performance is clearly emerging.
While the 'revenue increase' ratio for presidents in their 30s is 60.9%, it is 44.3% for those 70 and older, a gap of 16.6 points.
Also, companies led by presidents 70 and older are said to have the worst 'deficit' ratios.
The older they get, the fewer companies have revenue increases and the more have deficits.
These numbers show that becoming a toxic senior is directly linked to company performance.

Even more serious is that there were 462 'bankruptcies due to lack of successors' in 2024, a record high for 5 consecutive years.
This means that the problem of becoming a toxic senior is not an individual problem, but one directly linked to the survival of the company.

The Mechanism of Becoming a Toxic Senior — The Psychological Trap of a 'Fixed Mindset'

Why do people become toxic seniors?
Psychology offers a clear answer to this question.
It is the concept of 'Fixed Mindset' and 'Growth Mindset' proposed by Professor Carol Dweck of Stanford University.

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Fixed Mindset vs. Growth Mindset Comparison
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　　　　　　　　Fixed Mindset　　　Growth Mindset
View of ability　　　　Determined at birth　Can be developed through effort
Reaction to failure　　Concealment/Self-preservation　Utilize as a learning opportunity
Reaction to criticism　Do not accept/Defensive　Welcome as feedback
Others' success　　　Feel threatened　　　Stimulated/Use as reference
As a boss　　　　　Hinder subordinate growth　Help subordinate growth
Proponent　　　　　Stanford University Professor Carol Dweck
Book　　　　　　'Mindset: The New Psychology of Success' (2.5 million copies sold worldwide)
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The behavioral patterns of people who have fallen into a fixed mindset perfectly match the characteristics of a toxic senior.
They are convinced that their own ideas are absolutely correct, do not accept criticism, do not challenge new methods, and prioritize maintaining their own position over the growth of their subordinates.
This is not a 'change in personality due to aging,' but the result of a 'process in which a fixed mindset is reinforced as success experiences accumulate.'
The longer one lives, the more success experiences increase, and the stronger the gravitational pull to fixate on those success experiences becomes.
This is the mechanism by which one is drawn into the swamp of melancholy.

And Microsoft CEO Satya Nadella states that it was precisely this book by Dr. Dweck that triggered Microsoft's cultural transformation.
After taking office as CEO in 2014, he dramatically recovered the company's market capitalization by instilling a 'growth mindset' throughout the entire organization.
Overcoming a fixed mindset is not only an individual issue but also a management challenge that determines the fate of a company.

Summary

What can be done to avoid becoming an 'old fogey'?
My conclusion is simple.
'Use your past success stories as reference material. Do not use them as your conclusion.'

The essence of 'viewing the past to think about the new' lies here.
It is not about denying the past, but about 'viewing (ran)' the past from a high perspective.
And after viewing it, 'thinking (ko)' about new problems with your own mind.
Only when these two actions are combined does nostalgia turn into wisdom.

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Practical Checklist to Avoid Becoming an Old Fogey
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① When was the last time you accepted someone's criticism by saying 'that might be true'?
② Have you ever rejected an idea from a subordinate or junior colleague without a reason?
③ How many times this week have you said, 'Back in my day'?
④ When your opinion is overturned, does curiosity arise before anger?
⑤ Have you consciously acted to learn something from people younger than you?
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Becoming an 'old fogey' is most dangerous for those who think, 'I'm fine.'
The biggest characteristic of a fixed mindset is that the person themselves is unaware of it.

I personally like nostalgia.
I believe that the passion, failures, and successes of that era are all fuel for who I am today.
However, it is about not staying there, but continuing to view the old and think about the new.
I am convinced that this is the only way to face work while maintaining freshness as you age.
The world of IoT and smart writing that stak, Inc. is challenging has its common sense rewritten every year.
To keep fighting there, one must constantly raise new questions on the foundation of the past.
'Viewing the past to think about the new' is not just a four-character idiom for me, but my daily work attitude itself.