The Defining Decade: Why Your Twenties Matter – And How to Make the Most of Them Now

Meg Jay, PhD
New York, NY: Twelve – Hachette Book Group, 2012



The twenties are transformative and important years, but cultural myths and misinformation have downplayed their significance and left people in this age group wandering on an inconsequential plane somewhere between adolescence and adulthood. Dr. Meg Jay speaks directly to twentysomethings, affirming that these years matter, and calling for active participation in making the most of them for the sake of an intentional future.



Dr. Jay frames the cultural reality of twenty-first-century twentysomethings and makes a strong case for the necessity of reconsidering the importance of this decade. After identifying cultural myths about the twenties, Meg Jay examines three main areas: work, love, and the brain and the body. The author draws on her work as a clinical psychologist and educator to draw together common experiences and struggles of twentysomethings. With personal stories of clients and students sprinkled throughout the topics, the issues come to life.[1] Each of the three sections is divided into five or six short chapters (indicated in bold).


  • Introduction: Jay affirms that this is a book for twentysomethings, not just about She identifies three common cultural myths plaguing twentysomethings: “that thirty is the new twenty, that we can’t pick our families, that doing something later is necessarily the same thing as doing something better.”[2] In a society that simultaneously trivializes and fetishizes the twenties, young people often find themselves stuck in contradiction and uncertainty. Dr. Jay encourages readers to recognize “defining twentysomething moments”[3] as they consider work, love, and the brain and body.


  • Work: Here, Jay identifies identity capital and affirms that twentysomethings have the potential to invest in their dreams by taking action. Rather than clinging to likeminded urban tribes, Jay calls those in their twenties to connect with people outside of their normal circles, and intentionally use weak ties to explore new opportunities. The unthought known describes the inner hidden direction within an individual that may be suppressed by uncertainty about how to make choices and move forward. In a culture of comparison, twentysomethings face the “tyranny of the should”[4] and think, my life should look better on Facebook. In an attempt to customize life, Jay notices that young people conflate claiming and conforming when it comes to making decisions about work.


  • Love: In an upmarket conversation, Jay debunks the idea that getting married later is better. The culture encourages twentysomethings to not take relationships seriously, and “prizes independence and self-fulfillment”.[5] It is possible, however, to pick your family through intentionally clear goals and actions. Addressing the cohabitation effect, Jay notes that living together without clear commitment decisions tends to have a negative effect. She challenges dating down and encourages twentysomethings to reframe negative self-stories and identify what they want in relationships. A successful relationship, or being in like with someone involves personality compatibility more than having external things in common.


  • The Brain and the Body: In this final section, Dr. Jay considers physical realities of twentysomethings. The brain’s frontal lobe development (forward thinking), and peaking fertility in the mid to late-twenties (every body) are both important factors for twentysomethings to consider. Jay encourages young people to develop tools to calm themselves, acknowledging scientific reasons that those in their twenties often feel overwhelmed. Confidence, Jay says, comes from the outside in, as twentysomethings gain “mastery over their emotions.”[6] The “twenties are our best chance for change,”[7] and Jay points out that goals and action can help in getting along and getting ahead. She concludes by encouraging twentysomethings to cast of present bias, do the math, and make a plan to achieve their goals.



Dr. Meg Jay is a “clinical psychologist who specializes in adult development” and is especially “passionate about the twenties.”[8] With a doctorate in clinical psychology and gender studies from the University of California, Berkeley, Dr. Jay has focused on twentysomethings since 1999.[9] “She is an assistant clinical professor at the University of Virginia, and maintains a private practice in Charlottesville, Virginia.”[10] These extensive experiences with twentysomethings have clearly given Jay a unique and informed perspective, and her desire to help young people comes through clearly. Though psychotherapy is her primary lens, Dr. Jay speaks of twentysomethings as people rather than patients.



The Defining Decade is decidedly not a “Christian” book. Seeking to engage a wide audience around developmental and psychological issues, Dr. Jay develops her argument through sociological and psychological reasoning. Spirituality does not factor into the topics of work, love, body and mind as outlined by the author. Christian readers may be able to draw together implicitly underlying themes of community, purpose, and practice undergirding many of the topics covered, but these are not addressed theologically in the book. Though it was not written from a ministry (or even overtly Christian) perspective, the implications of this book reach meaningfully into those areas.



Dr. Jay is clear that The Defining Decade is meant to help twentysomethings navigate life. By writing directly to them, she validates their existence and experiences. Jay invites parents, bosses, teachers, and others to “listen in” on the conversation.[11] As she tells stories of former clients and students, the author hopes that twentysomethings will see their own struggles reflected and find meaningful guidance. Sections one and two describe common pitfalls of work and love based on the false messages today’s culture gives twentysomethings. Jay aims to highlight the falsehood of these messages through research and personal examples of people who have been harmed by them. In section three, she integrates physical realities of the mind and body, which contribute to navigating this crucial decade of life. In the end, Dr. Jay aims to inspire twentysomethings to take control of their lives, saying, “you are deciding your life right now.”[12]



The Defining Decade largely accomplishes its goals and is well received by twentysomethings. The book’s direct approach and behind-the scenes view into the psyche of twentysomethings puts the issues into a relatable context. Weaving together these real stories, science, and Dr. Jay’s seasoned suggestions is a major strength of the book. The author convincingly demonstrates that the twenties matter, and inspires young people to do something about it. It is refreshing that her message is aimed at the very audience she is speaking about.

Though the book strongly motivates, there are fewer places where actual tools are given for young people to do the work Jay suggests. The Big Five personality chart in Jay’s “love” section is the most practical piece that could be put into action directly from the pages of the book. Twentysomethings may finish this book wishing for more practical tools such as this. Additionally, The Defining Decade seems to be primarily oriented toward a white, upper middle class audience. Most examples deal with college graduates, many of whom are in psychotherapy.  

Additionally, much of this book feels like accomplishment-based career counseling.

Though not written from a Christian perspective, this book could be a great tool for collegiate ministers. To a large extent, The Defining Decade deals with concerns that come up in the later half of the twenties. Framing the cultural myths, however, and communicating with younger twentysomethings about these issues is paramount. The questions around work and love will be familiar to ministry leaders who work with college students, but Jay gives a longer-reaching perspective that extends well beyond college. Whether collegiate ministers use this book as a referral for students or simply a reminder for themselves about the significance of the twenties, The Defining Decade is a book that would be helpful for those who work with college students.


[Review by Sarah Logemann]


[1] Names and details were changed for privacy, and the author “created composites from those with similar experiences.” Jay, M., The Defining Decade, Author’s Note.

[2] Jay, M., The Defining Decade, xii.

[3] Ibid., xvi.

[4] Ibid., 46.

[5] Ibid., 87.

[6] Ibid., 160.

[7] Ibid., 160. 

[8] Ibid., xix.

[9] Ibid., xiii.

[10]Ibid., About the Author.

[11] Ibid., xiv.

[12] Ibid., 201.