Strength and Weakness in the Third Third of Life - Reflections on "From Strength to Strength" by Arthur C. Brooks

By Mark D. Roberts

March 31, 2022

De Pree Journal

I recently finished a book filled with wisdom for those of us in the third third of life. Technically, Arthur Brook wrote this book for folks in the second half of life, as indicated by the full title of his book: From Strength to Strength: Finding Success, Happiness, and Deep Purpose in the Second Half of Life. But, of course, the third third fits in the second half of life. So, what Brooks has written is directly relevant to third thirders like me, and also to people in their 40s and 50s.

I’ve always enjoyed the writings of Arthur Brooks (who, by the way, is not related to the New York Times columnist David Brooks, though their writings often overlap thematically). Arthur Brooks’s resumé reveals fascinating diversity: world-class French horn player, student and professor of public policy, president of a think-tank, and professor at Harvard (Business and Kennedy schools). Brooks has written nine books, several of which are best sellers. His latest book, published in February 2022, is From Strength to Strength.

Strength? Or Weakness and Decline?

As you begin this book, you might at first wonder where the strength is. Brooks seems much more interested in writing about weakness, or, to be more precise, decline. In fact, his first chapter has this cheery title: “Your Professional Decline Is Coming (Much) Sooner Than You Think” (p. 1). In this chapter, he says things like:

Here is the reality: in practically every high-skill profession, decline sets in sometime between one’s late thirties and early fifties. Sorry, I know that stings. And it gets worse: the more accomplished one is at the peak of one’s career, the more pronounced decline seems once it has set in” (p. 4).

Repeatedly throughout the book, Brooks underscores the reality of physical and especially mental decline. Consider this example:

Here is the bottom line, fellow striver: when it comes to the enviable skills that you worked so hard to attain and that made you successful in your field, you can expect significant decline to come as soon as your thirties, or as late as your early fifties. That’s the deal, and it’s not fun. Sorry (p. 22).

Brooks backs up claims like this with evidence from academic disciplines such as psychology, medicine, gerontology, and neuroscience. He also shares his own experience of personal decline, something that happened rather early in his life when his impressive musical skills began to diminish.

From Bad News to Good News

If you were to stop reading From Strength to Strength at the end of chapter 1, you’d tell your friends, “That book was such a downer!” But, as you might have guessed from the book’s title, Brooks doesn’t end with the bad news of decline. Rather, he uses this unhappy news to introduce the good news of positive changes in the brain that come with age. He begins his second chapter, “The Second Curve,” on this pleasant note:

Decline is unavoidable. Period. But aging isn’t all bad news. . . . In fact, there are some specific ways in which we naturally get smarter and more skillful. The trick to improving as we age is to understand, develop, and practice these new strengths. If you can—and I am going to show you how, don’t worry—you can transform decline into incredible new success (p. 23).

The “naturally smarter and more skillful” reality comes with what Brooks calls “The Second Curve.” He draws from the well-respected research of Raymond Cattell, who in 1971 published a book proposing that human beings have two types of intelligence: fluid intelligence and crystallized intelligence. Fluid intelligence is the ability to think flexibly and reasonably, to be creative, and to solve novel problems. Crystallized intelligence is “the ability to use a stock of knowledge learned in the past” (p. 27). Younger brains tend to have an abundance of fluid intelligence, while older brains major in crystallized intelligence. Brooks puts it this way, “When you are young, you have raw smarts; when you are old, you have wisdom. When you are young, you can generate lots of facts; when you are old, you know what they mean and how to use them” (p. 27).

So, according to Brooks, the unavoidable reality of decline that we experience as we get older is connected to our aging bodies and brains. In particular, our loss of fluid intelligence means we will not be able to do many of the things that had once been essential to our professional success. But there is hope, according to Brooks. And that hope has to do with jumping from the fluid intelligence curve (the first curve in life) to the crystallized intelligence curve (the second curve). Picture a graph with the first curve peaking around age 30 and then declining. The second curve begins around age 30 and hits its peak at age 60 and beyond. Brooks writes:

This is a big finding for you and me—huge, actually. It says that if your career relies solely on fluid intelligence, it’s true that you will peak and decline pretty early. But if your career requires crystallized intelligence—or if you can repurpose your professional life to rely more on crystallized intelligence—your peak will come later but your decline will happen much, much later, if ever. And if you can go from one type to the other—well, then you have cracked the code (pp. 27-28).

In particular, Brooks argues, we will flourish in our later professional lives if we learn to depend less on innovation (requiring fluid intelligence) and more on instruction (requiring crystallized intelligence). Brooks himself exemplifies such a shift, in that he resigned from his leadership of a think tank to become a professor at Harvard. As a teacher, he’ll draw more from crystallized intelligence (which is growing) than from fluid intelligence (which is shrinking).

So, as we get older, we will flourish if we can jump from the first to the second curve. As Brooks writes, “So here’s the secret, fellow striver: Get on your second curve. Jump from what rewards fluid intelligence to what rewards crystallized intelligence” (p. 40). That’s the main point of From Strength to Strength. Brooks says, “The rest of this book, therefore, is dedicated to helping you make the jump (pp. 40-41).

More Than Thinking

As you finish chapter 2 of the book, you might think the rest of it is going to focus on thinking, on various ways to enhance and use our crystallized intelligence. But, in fact, Brooks offers advice on far more than just how we think. His “program” is about thinking, yes, but also about feeling, relating, growing, and being. Brooks summarizes his whole book in this way:

Use things. Love people. Worship the divine (p. 215).

No tricks here for how to change or enhance your brain. Rather, a formula for living in a richly meaningful way, focusing on what matters most in life.

The inclusion of “Worship the divine” might surprise you, given that From Strength to Strength is not a “Christian book” per se. You won’t find it in the religion section of a bookstore (if you can find a bookstore). It would tend to go in the “Personal Development” or “Self-Improvement” sections. But Brooks is open about his Christian faith and it informs his work at several points. Interestingly, the title of his book comes from the Bible, from a passage with which Brooks begins his book:

Blessed are those whose strength is in you,
whose hearts are set on pilgrimage.
As they pass through the Valley of Baka,
they make it a place of springs;
the autumn rains also cover it with pools.
They go from strength to strength,
till each appears before God in Zion (Psalm 84:5-7).

In a chapter entitled “Make Your Weakness Your Strength,” Brooks begins by asking “Who is the most successful entrepreneur in human history?” (p. 171). His answer surprised me. “For my money, that distinction, hands down, goes to Saul of Tarsus—later Saint Paul, to Christians” (p. 171). Now that is a happy surprise, indeed. Brooks sees Paul’s entrepreneurial church planting effort as chiefly responsible for the founding of Christianity. Yet, according to Brooks, it wasn’t Paul’s great strength as an innovator, leader, or theologian that explained his influence. Rather, it was his Paul’s ability to acknowledge his own weakness and to be open about this with others, thus providing a basis for deep and enduring relationships. Paul leveraged his decline for the sake of the church and its success.

My Response to This Book

Photo by Gage Skidmore, Creative Commons License

At this point, I’d like to share with you my response to From Strength to Strength. I enjoyed reading it, to be sure. Brooks is a fascinating and readable author. His ideas are solid and his stories are engaging.

I certainly affirm the main idea of this book. If we are going to flourish in the third third of life, then when we need to pay attention to what’s happening in our lives, including our bodies and brains. We do need to learn to be okay with letting go of abilities that were stronger when we were young. And we need to discover the abilities that are growing in us as we age, and learn how to develop those abilities. For this to happen, we require not only a change in thinking but also a new way of living, a new kind of being in the world. “Use things; Love people; Worship the divine” sums it up well.

Use of Research

I appreciate the fact that Brooks draws generously from scholarly research related to aging, including psychology and neuroscience. His use of the fluid intelligence – crystallized intelligence distinction is solid. But it does seem to me that he over-simplifies what is happening in our brains as we get older. Though the shift in intelligence is significant, to be sure, so much more is going on that matters. To cite just one example, lots of research shows that, in general, as people get older they are happier. Older adults tend to be healthier mentally than younger adults. (See Mandy Oaklander, “Old People are Happier Than People in Their 20s,” TIME, 8/24/2016). Flourishing in the third third of life may well depend on a jump from fluid to crystallized intelligence, but that’s just one part of a much larger personal growth experience.

Plus, given the pioneering work of Howard Gardner, it has become increasingly common these days to talk, not about intelligence in the singular, or even about two kinds of intelligence (fluid and crystallized), but about multiple intelligences. Gardner has proposed that “human beings have a number of relatively discrete intellectual capacities.” Our multiple intelligences “constitute the human intellectual toolkit. Unless grossly impaired, all human beings possess the capacity to develop the several intelligences” (quotations from Gardner’s Multiple Intelligences website). I don’t know if researchers have begun to work on how Gardner’s theory affects our thinking about aging, but I would anticipate learning that certain intelligences (more than just fluid) tend to decline as we get older while others (more than just crystallized) improve. At any rate, the theory of multiple intelligences would suggest that Brooks’s approach is on the right track, but too simple.

Brooks is so eager to emphasize the reality of decline as we get older that, at times, he sometimes skews the evidence too far in the direction of his thesis. For example, he claims that “by middle age, entrepreneurial ability is plummeting” (p. 7). He cites some research to back up this point. He also acknowledges research that shows how older entrepreneurs are successful, but doesn’t give that much weight, though without explaining why. Brooks seems to be unaware of the fact that more and more research points to the entrepreneurial ability and success of older adults. For example, a recent article in reported on a study of 2.7 million startups. The article had this headline: “A 60-year-old startup founder is 3 times as likely to found a successful startup as a 30-year-old startup founder.” Now, this doesn’t prove that the 60-year-old still has the fluid intelligence of a 30-year-old. It might, however, show that crystallized intelligence is worth more than we had expected when it comes to being a successful entrepreneur.

Narrow Audience?

If Brooks focuses too much on the evidence that supports his thesis, he also tends to focus too much on a certain kind of reader. His book begins with a story about his encounter with an older man who was both very successful and very famous. At times, while reading From Strength to Strength, it felt to me as if Brooks was speaking mainly to people like this man. Brooks acknowledges that he’s writing for those who would identify as a “fellow striver” (p. 22). He envisions his reader as someone who has been “successful in your field” (p. 22). He wants to help this person “transform decline into incredible new success” (p. 23). I get the feeling that success is a big deal to Brooks, and that his book will resonate mainly with those who share his love of success if not also his experience of having achieved unusual success in his professional life. I wonder if folks less oriented to success will find From Strength to Strength to be as relevant as those who are, like Brooks, über-successful strivers.

So, when Brooks talks about shifting from innovation to instruction, using examples of college professors who are flourishing as they get older, I wonder how many of his readers will relate. Brooks was able to move from leading a think tank to being a Harvard professor. That’s fantastic. But how many of us could envision such a future? It does seem that at times Brooks’s perspective is unapologetically elitist, and I say that as someone who has certainly dabbled in elitism.


Nevertheless, I found From Strength to Strength to be informative and encouraging, filled with the sort of wisdom I associate with Arthur Brooks. He has challenged me to think more carefully about the choices I’m making about where and how to invest my limited time and energy. He has also helped me to think about the things that motivate me to put so much of myself into my work that I can miss out on what gives me the most joy and meaning.

I was particularly moved by and grateful for a prayer that Brooks shared, one that he wrote for himself. It is based on the “Litany of Humility” written in the last century by Cardinal Rafael Merry del Val. I’ll close these reflections on From Strength to Strength with Brooks’s rendition of this prayer:

From putting my career before the people in my life, deliver me.
From distracting myself from life with work, deliver me.
From my drive to be superior to others, deliver me.
From the allure of the world’s empty promises, deliver me.
From my feelings of professional superiority, deliver me.
From allowing my pride to supplant my love, deliver me.
From the pains of withdrawing from my addiction, deliver me.
From the dread of falling into decline and being forgotten, deliver me (p. 62).

I say “Amen” to that!

Mark D. Roberts

Senior Strategist

Dr. Mark D. Roberts is a Senior Strategist for Fuller’s Max De Pree Center for Leadership, where he focuses on the spiritual development and thriving of leaders. He is the principal writer of the daily devotional, Life for Leaders,...

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