Hace 26 años mi papá corrió emocionado por las calles de Miraflores comprando arreglos florales y diciéndole a cualquier persona que se le acercara : “¡son dos! ¡Son dos niñas!”, mientras levantaba sus dedos en una inconsciente señal de victoria

That translated excerpt is from a post I wrote over eight months ago as I handed the reins of Latin American Regional Editor over to friend and colleague Eddie Ávila. Though I knew I’d eventually meet Juliana, neither she, her twin sister, nor her father seemed like tangible, real people. They were much more like characters in one of my favorite books. And that book happened to be Juliana’s blog.

Fast-forward to Nochebuena, or Christmas Eve, and I was sitting in the Rincón family home listening to father Rincón talk science with Steve while Juliana and Liz played off each other’s stories as twins are apt to do.

It was a fun week while Liz was here, visiting from Costa Rica, and Noah was here, visiting from New York. We drank too much aguardiente, had a dinner party, and compared notes on the pretty hipster girls at Parque Poblado.

The same day that Noah left early in the morning to get to New York just before Time Square’s famous ball-drop, Juliana came over to our apartment with Liz, Risë and Darío. Risë is from the US, Dario is from Bogotá, and both live in Monteverde, Costa Rica. A generation forever in flux we are.

Eventually, a bottle of wine and several beers later, the conversation turned to nature and nurture and what makes us who we are. A perennial conversation, with its multitude of flavors and variations: are people innately good or evil? If I had your life and you had mine, would we be each other? Was I born a jealous person or did my experiences shape my personality?

And on and on.

During this particular conversation, however, I stayed quiet. I’ve been through it too many times; in my head, with close friends, family, and complete strangers. My only real opinion on the nature versus nurture debate is that our position probably says more about how we like to be identified by others than it does about our analytical reflections on socialization and genetics.

So, instead of writing an opinion, I’ll share three short stories.

1989: My sister was born on November 15, 1989 at 8:40 p.m. I remember because I wasn’t entirely happy that she chose to enter this world during my favorite TV show, Doogie Howser. As it turns out, it was the only time she would arrive early. (Actually, at 18-years-old she’s become a pretty punctual adult.) I was 9-years-old, soon to be 10, living in Dublin, Ohio, far from my friends and classmates. So I got to spend a good deal of time watching her grow up.

As a baby and infant she was quiet and tranquil. Mostly content, but rarely giggly and giddy. The only exception was when she was in crowded, noisy areas for long periods of time. She had a very clear limit and when she reached that limit she would break down. Cry. Sob. And then, a couple hours later, she’d be fine again.

Just over 18-years-later, a beautiful and intensely intelligent young woman, she is still quiet and tranquil, mostly content, and only occasionally giggly and giddy. She still has her limit.

1994: I’ve never met my biological father. Though I’ve heard a name mentioned, I don’t know that I believe it. And, while you might not believe me (nor would Joseph Campbell), it’s a topic that barely crosses my mind.

Growing up in junior high and high school, my best friend did not know his father either. We both had step-dads who we both called dad and it seemed completely normal. We never really talked about it.

Until the summer of ‘94 when my best friend invited me to travel with him to meet his biological dad for the first time. We were both just 13-years-old. We boarded a plane together and off we went. His biological dad – who he simply called by his first name – must have picked us up at the airport, but I don’t really remember.

What I do remember thinking is how similar my best friend and his biological father were. Facial expressions, mannerisms, personality. We didn’t talk about it then. We explored the city, raced in go-karts, and met a prostitute named BamBam on the public bus who asked us for advice on her impending move to Montana, where she figured business might be better. Years later he told me that trip was a huge realization for him.

2007: Like I wrote just a couple days ago, some of my most reflective moments come when I’m running and listening to podcasts. Last fall I was running around Lake Merritt in Oakland when I heard a podcast that was so well produced it made my hairs stand on their ends. Oakland’s hills seemed greener than ever and the sky took on such a deep hue of blue that it appeared to have a whole other texture.

The podcast is about 15 minutes long. I can assure you that there are worse ways to spend 15 minutes. It describes the first meeting between two identical twin sisters 35 years after they were purposely separated at birth as part of a research study to explore nature versus nurture.

It is, according to twins expert Lawrence Wright, “practically the perfect study.” Each set of identical twins was separated and raised by different families. Neither the twins nor the adoptive families knew they were part of a study. And researchers took notes as each twin grew up with the exact same DNA, but in different environments.

The results of the investigation were never published. Neubauer, the principal investigator, realized that the ethics of the study would be too controversial. The results have been sealed until 2066 and given to an archive at Yale University. In the podcast we’re only given the briefest hint of what the researchers learned. In a crackling phone interview, Neubauer echoes the theories of Maslow: if the hierarchy of needs are met, then each person will self-actualize to become who (s)he ‘really is.’ Of course, this could reveal more about Neubauer’s own ideology than the quantitative and qualitative records of the study.

I guess we won’t know until 2066. And by then, I’m sure that the human genome will have told us much more about both nature and nurture than the study ever could.