"The Defining Decade" is an insightful collection of case studies from Dr. Meg Jay that challenges the perception of what it means to be a 20-something in present-day America. She visits with clients and shares stories related to work ethic and job hunting, relationships, love, and biological factors that prove to shape their twenties. The premise of the book is to instill in young people that the short ten years between twenty and thirty are not merely there to be wasted, but instead to be used to invest in themselves and shape the rest of their lives. It aims to create a sense of urgency in young people that might assist in making the initial decisions that will lead to an avalanche of opportunities. For “twentysomethings,” as they are referred to throughout the book, the time for action is now, and the choices they make will forever impact their future successes and failures. Jay begins by outlining several common “myths” that she wishes to disprove throughout the book. “I use research and clinical experience to dispel myths about the twentysomething years: that thirty is the new twenty, that we can’t pick our families, that doing something later isn't necessarily the same thing as doing something better.”

The first section of the book is about work and an original idea of “Identity Capital.” Just as successful businesses have capital used to make products, successful people have capital used to make lives. Jay believes that the collective work in the areas of relationships and education amasses a total asset value. It is these political connections, personality traits, talents and work ethic that distinguish one person’s Identity Capital from another’s. In this section, Jay comments on the importance of weak ties: the secondary relationships we build with those that we may not even realize. These are the high school acquaintances we call in favors from; the people that get us interviews and opportunities that we may have otherwise not had. These types of relationships are a key ingredient in the recipe for Identity Capital and are often underestimated, according to Dr. Jay. This section focuses on the myth that doing something later isn’t necessarily the same thing as doing something better. Twentysomethings and those even younger should consider this concept of Identity Capital immediately and begin to build weak ties.

The second section of Jay’s book focuses on relationships and love and how imperative they are to achieving true happiness. The most important decision people make in life is not which college to attend or what to major in, it is not what job they get or where they live. While all of those things are important and should be taken into serious consideration, the most important is who they marry. An opening quote in the section states that “society is structured around distracting people from things that have a huge impact on happiness and directing focus to those which have a marginal impact on happiness” (Jay, 70). Jay states and reinstates the importance of marrying a person with whom someone can be truly happy. The concept of marrying somebody out of convenience or simply to meet a lifetime timeline is a tragedy and cannot be taken lightly. This falls under the myth that people cannot pick their families. Certainly one cannot pick their nuclear family; mothers, fathers, sisters and brothers are all people that must be accepted. However, people can choose those with whom they have family-like relationships. They can also choose those with whom they start a family of their own.

A subsection under “Love” focuses on the concept of cohabitation, living with one another before marriage or even engagement. Meg Jay references experiments done to test the validity of “test driving” a marriage before deciding to go through with it. Studies show that when a marriage is tested with cohabitation before engagement, the marriage is much more likely to end in divorce; this increased likelihood is referred to as the “cohabitation effect” (Jay, 91). However, when cohabitation takes place after the engagement, there is no difference in the strength or length of the marriage. This can be attested to many factors, but the main one is commitment. When two individuals have decided to commit to one another through an engagement, they are more likely to change and accept differences to meet the needs of their significant other. This section dispels the myth about how waiting longer is necessarily making the situation better. It does not matter the age of the couple, but instead the level of commitment they are willing to give forth in order to sustain a marriage.

The final section of the book is called “The Brain and Body,” and focuses on how our biological makeup is changing in our twenties and the effects it can have on decision making and personality development. The first section is a summary of the history of Phineas Gage, a psychology-based case study in which a railroad accident leads to a man’s personality change. The rest of it discusses the effects of having positive outlooks and building confidence. Jay talks about how one cannot simply configure pseudo-confidence but must instead put themselves in a situation to gain authentic confidence. This is developed through succeeding in tasks that may have initially seemed daunting. The rule of ten thousand is a recurring theme of this section. This is just the concept that mastering any skill requires ten thousand hours of focused practice. It is easy to become distraught and discouraged while searching for a skill, but diligence is necessary.

I would have to agree with the comment made by Slate.com, “Any recent college grad mired in a quarter-life crisis or merely dazed by the freedom of post-collegiate existence should consider it required reading.” This book has absolutely changed my approach to the next four years of my life in college and how I will spend my twenties. Waiting until later to get important things done on life’s “to-do” list is not the approach to take, especially if I want to get ahead of the rest of my generation. I will benefit from picking my new nuclear family in the near future; maintaining friendships and weak ties will benefit me as well. This book has proven that thirty is most certainly not the new twenty and that twenty may be a lot closer than some of us would like to admit. This next decade of our lives can be both fun and productive, but it will absolutely be defining.