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The Psychology of 30

30 is the new 20, 40 is the new 30. . . . However the saying goes: I am ready to be 30!

My teenage years were trying, but fun. My 20’s were exploratory, to say the least. My 30’s, well I can’t say yet, but I have feeling they will be adventurous and rewarding!

Why is it we celebrate big “milestone” birthdays like the decades? Many in our society see it as a mile-marker for their life. It’s a time to ask: Did I accomplish all the goals I wanted to? Am I where I want to be in my career? Am I paying attention to what is important in life at this moment? Much like a new year’s resolution, a milestone birthday is a chance to reflect on the past decade, see how far we’ve come, and what we still have left to accomplish.

The Psychology

An interesting study, published by the Public Library of Science in 2015, discussed the facts behind why we see these milestone birthdays as so pivotal. First of all, it’s true. We do use these landmark birthdays to evaluate our lives. We focus less on daily emotional familiarities and step back to gage our big picture life. Here’s what researchers found:

  • Milestone agers (defined as those who are 30, 40, 50, or 60 years old) are focused more on their life satisfaction than others.

  • This is aligned with other research that the milestone ages tend to be more objective in their self-evaluations than subjective

  • Milestone agers focused more on events that brought a negative emotion, than those with a positive.

Unfortunately, there is not a lot of other current research out there on milestone birthdays. Some research has found that, in psychiatric patients, suicide often happens within a month of one’s birthday. Another study (an old study, it was published in 1978) found that, and I quote: A critical point “for women [is their] 30th birthday. For women who have not had children, attitudes that childbearing is difficult after 30 can cause depression or other problems when women are confronted by the thought that they will probably not have children. It can also mark the end of youth, which is more important to women than to men. ”

Yeah, this is definitely not where I am right now. No wonder this research hasn’t been duplicated.

However, a similar study found cultural differences in how we view milestone ages. European Americans (such as myself) tend to focus more on positive life events when evaluation their last decade, whereas Asian Americans tend to focus one more negative events. Why these cultural and gender differences? We’re not sure yet. It’s clear, the authors note, more scientific research is needed on these milestone.

Real Life: Turning 30

This week, as I turn 30, I am reflecting upon both the negative and the positive of the last decade. The positive because a lot of great things have happened in my life, and I’m pretty proud! I completed a BS, MA, and am more than halfway through my Ph.D. program (which I never had planned in the first place); I have made great friends, and kept old amazing friends close; I have traveled the world and learned more about myself in the last decade that I thought I ever could. On the other side of this week, I am reflecting upon things that have had negative emotions attached to them. I have suffered a near-death experience (which yes, I am going to be posting about soon, I promise!) as well as mental health struggles of my own. But I look back at these and see the positive: I lived, I overcame, and now I’m truly living my best life!

I’ll be spending my 30th birthday with my boyfriend (who, shout out, I am madly in love with and helps me edit these posts!) and eight close friends including some genuinely good people I just met six months ago, my best friend who has been through all my ups-and-downs with me since 3rd grade, and my younger brother who always reminds me how important family is. I can’t think of a better way to reflect upon a roller coaster of a decade and look forward to more excitement and unpredictability to come.

The Real Life Takeaway

Turning a decade milestone age this year? Happy Birthday! Take the opportunity to look back on the positive and the negative. What have you accomplished, but more importantly: what have you learned?

My motto for my 20’s was a quote by J. R. R. Tolkien: “Not all those who wander are lost.” I was wandering, only to find myself. Now that I have found myself, I want to help others. Guess my 30’s will have to find a new motto!

My advice for those in their 20’s: take opportunities and risks; embrace the negative and the positive in life, it’s inevitable; don’t compare yourself to others. Most importantly: You can always learn from others; everyone knows something you don’t. If you are the smartest person in the room, you are in the wrong room.


Miron-Shatz, T., Bhargave, R., & Doniger, G. M. (2015). Milestone age affects the role of health and emotions in life satisfaction: A preliminary inquiry. Plos ONE, 10(8),

Notman, M. T. (1978). Women and mid-life: A different perspective. Psychiatric Opinion, 15(9), 15-25.

Wirtz D, Chiu CY, Diener E, Oishi S. What constitutes a good life? Cultural differences in the role of positive and negative affect in subjective well-being. J Pers. 2009; 77: 11671196. doi: 10.1111/j.1467-6494.2009.00578.xPMID:19558439

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