Longevity: The New Compound Interest

Compound interest is defined by wikipedia as:

interest accumulated from a principal sum and previously accumulated interest. The formula for compound interest is as follows:

Where:

• A is the amount of money accumulated after n years, including interest.
• P is the principal amount (the initial amount of money).
• r is the annual interest rate.
• n is the number of times that interest is compounded per year.
• t is the time in years.

Understanding compound interest can be challenging because we naturally perceive time in a linear way, making it difficult to understand exponential growth. Additionally, seeing the benefits of compound interest requires consistency and patience.

The interesting thing about this principle is that it applies not only to finance but also to expertise, knowledge, and habits. James Clear talks about this in his book Atomic Habits sharing that self-improvement can compound similarly to that of finance. Specifically, he shares that if you can get 1% better each day, over time you can see a 37% improvement.

I personally find it a hopeful message that plateaus can be surpassed when my attention focuses on small improvements over time usually through deliberate practice. The problem I have with the above image is that I don't really know what better means. It has been a while since I have read the book and I assume that Clear explains it but for now I find specific examples in my own life insightful.

Also, aside from giving a brief explanation of the principle and making a connection that Clear has already made, I am writing this post to point out that the principle can be applied to even more granular skills and habits. The two topics that I want to write about specifically is productivity and longevity.

Productivity

As anyone who has browsed the self-help section of a library can confirm, productivity is one of the most prevalent topics. In my first few years in my 20s, I read so many of these books and really got sick of the endless amount of anecdotes given and generic surface-level advice. Every once and a while, I would find a gem and that would improve my approach to prioritizing, planning, and executing. Some of these sources include:

• Notion in 2019
• Alfred in 2020 (which was later replaced by raycast )
• Tim Ferriss' Podcast in 2020
• How to Take Smart Notes by Sönke Ahrens in 2021
• 4000 Weeks by Oliver Burkeman in 2023

Again, I couldn't fully pinpoint the point in which I felt that my productivity improved from its baseline but I can say that the ability to formulate what is important to me and then being able to actually make it happen opens so many doors for my life.

Is it really exponential though?

The gains I saw in productivity were incredibly helpful but were they exponential? Below is a chart that I asked Claude to make to describe the general phenomenon of a someone becoming an expert in a field.

Clearly, the line isn't exponential as it is barely not a plateau. So then why would I bring up compound growth in the first place? Humans are genetically limited and so for each skill or habit, we each hit a type of "slow grow plateau" at different points in our paths to expertise in a subject.

To straw man the exponential point, think of how difficult it would be for a person to get into the WNBA or NBA who is 4 feet tall. Yes, you can train and experience the rapid beginner gains but at some point, the genetic limit is reached and the growth begins to become a lot more difficult.

In terms of how someone can make an impact in the world, finding which skill you can have the biggest genetic advantage and therefore largest rapid beginner gains becomes paramount. Are you a 7 foot tall person with good hand eye coordination? Maybe basketball is your sport. Are you an excellent listener with a high emotional intelligence? Maybe therapy is your calling. To be clear, I want to point out that I don't think simple physical attributes like height determine the level of expertise one can achieve, I think humans are more complex than that. ( If you want a fun movie on this topic, check out Gattaca ).

But what happens when you do find a skill that you enjoy and could legitimately become the best in the world at, won't that skill just degrade over time due to age and health-related issues?

Longevity : Maintaining and Valuing Skills Over Time

I define longevity as the goal of increasing both healthspan and lifespan. Healthspan is the number of years in good health and lifespan is the number of years you live. The reason I use the term longevity as opposed to health is because I find the accompanying terminology to help me understand the complex topic better.

I originally started thinking about this topic in 2021, when I was curious how I could improve my exercise routine aside from the current calisthenics I was doing. I found out about Peter Attia via the Tim Ferriss podcast and was intrigued by his multifaceted approach.

Via Peter Attia and others, I slowly began to realize that there were so many things that I had not considered that improve my life like sleep, nutrition, proper footwear, proper skincare, etc. Similar to productivity, each facet complements the other. Good sleep boosted my recovery, which helped me exercise more, which helped me want to eat better, and the cycle goes on and on like that.

Longevity begins to become really interesting when it allows a person to maintain a high level of expertise in a field for a long period of time.

One of the greatest examples of this is Lebron James. LeBron James exemplifies maintaining a high level of expertise over a long period due to his exceptional longevity and consistent elite performance in the NBA for over two decades. Entering his 21st season at age 38, he continues to be a top player in the league, averaging impressive statistics (28.9 points, 8.3 rebounds, and 6.8 assists per game last season) that far surpass other players who have played as long, demonstrating his unique ability to adapt his game and maintain peak physical condition well into his late 30s. While most people's skills start to decline at a much younger age, Lebron has been able to follow the trend of maintain his skills and arguably becoming an even better player.

But even if Longevity can push the skill level slightly higher or keep the line at maintence level for slightly longer, it still doesn't seem to be exponential.

Leaps

This is where I think the most important part of growth comes in. If high levels of expertise can be maintained for longer periods of time, the chance to achieve something extremely impactful increases. The reason boils down to the accumulation of shots on goal and the concept of leaps.

A leap is a sudden breakthrough in understanding. Leaps occur when we make connections between different areas of knowledge or when we have sudden breakthroughs in understanding. A shot on goal is a single attempt to make a leap. For example, a researcher goes to work doing deliberate practice in their field for 10 years before having a sudden breakthrough in understanding.

Aside from genetic changes, leaps are one of the primary ways humanity progresses. For example, Einstein's theory of relativity catapulted the scienctific community's understanding of space and time. The addition of the attention mechanism to language models in the Attention is All You Need paper made a giant leap in capablities and is the primary driver of the current AI revolution. A last example is that of Dick Fosbury who discovered the "Fosbury Flop" which enabled him to revolutionize the sport of the high jump.

The above line chart isn't exponential but is much better than the previous chart! Increasing the number of well-aimed shots on goal in your field of expertise will increase the number of potential leaps you can make.

Think if Mozart could have lived far past the age of 35, what masterpieces could he have created?

In conclusion, while skills don't compound exponentially and are tied to our genetic limitations and amount of health-related issues, the best way to increase the amount of leaps and discoveries we can make in our lifetime is to frame it as a game of compound interest similar to that of finance. Although continually investing into longevity will not have the same affects as reinvesting your financial gains, the underlying principle is the same. The key takeaway is that the best way to increase the number of leaps and discoveries we can make in our lifetime is to continually invest into longevity alongside your expertise so that you can continue to make leaps in your field for a longer period of time after you have reached the level of an expert.