As twins, Jack and Oskar shared the same DNA, the same nature, and yet, they emerged radically different people. Born in Trinidad in 1933, they were six months old when their parents divorced. Oskar went to Germany with his Catholic mother, while Jack stayed with his Romanian Jewish father. Oskar grew up as the Nazis rose to power, greeted the school principal with “Heil Hitler,” and later joined the Hitler Youth movement.

Jack, meanwhile, always thought of himself as Jewish, but didn’t feel its significance until he was 15 years old and was sent to Venezuela to live with his aunt. A survivor of Dachau, she was the only person from his father’s side to make it out alive.

After the war, Jack’s aunt encouraged him to move to Israel and so at 16, he made Aliyah and joined the Israeli Navy, ultimately becoming an officer. In 1954, Jack went to Germany to meet his identical twin. They were 21 when they met for the first time as adults.

Psychologist Nancy Segal tells the story of that encounter in her book “Indivisible by Two: Lives of Extraordinary Twins.” Jack and Oskar examined one another as if they were looking at an alien, even though the other’s appearance should have been entirely familiar to them. Their cultural differences were as immediately apparent as their physical similarities. Casting a wary eye at Jack’s Israeli luggage tags, Oskar removed them and told his long-lost brother to tell others he was coming from America, not from Israel.

Suffice it to say that first reunion did not go well. Two brothers – one raised a proud Jew who served in the Israeli Navy and the other raised a German Catholic who had risen in the Nazi Youth movement and been taught to hate Jews. Because of the language barrier they couldn’t communicate much. At the end of the visit, they shook hands like strangers and Jack set off to San Diego where he lived the remainder of his life.

In 1979, Jack read about a study being done on twins and the great debate between nature and nurture. He asked if he and his brother could participate and thought after 25 years it might provide another opportunity for them to see one another and develop a relationship.

Jack Yufe and Oskar Stohr

They met at the Minneapolis airport and to their amazement discovered they were wearing the exact same thing – a white sports jacket, similar shirt and wire- rimmed glasses. During the study, they learned that they had so much in common. Both were stubborn and arrogant, both fiercely competitive. Both read books from back to front, both sneezed incredibly loudly, they walked in a similar fashion, and they both wore rubber bands around their wrists.

And yet, with all that nature gave them in common, nurture had made them different. They could never agree on issues about Israel and her enemies or who was responsible for World War II. Oskar’s repeated reference to German soldiers as ‘we’ infuriated Jack. In a BBC documentary about the twins, Jack describes that they tried to like each other and enjoy each other’s company but there was always something in the background that they could not tolerate about one another. Jack died a few years ago at 82 years old. Oskar passed away in 1997.

As twins, Esav and Yaakov shared the same DNA, the same nature, and yet, they emerged radically different people. One became a patriarch of our people and the other a great villain of Jewish history, the progenitor of Edom, the exile in which we remain until this very day.

The name Esav comes from the Hebrew word "asui" which means complete, or finished product. The simple way to understand this is as a superficial description of Esav’s appearance. He was physically mature, covered in hair and appeared complete, fully grown as an adult.

But Esav’s name is not just about his physique; more importantly it is about his spirit and approach to life. Esav sees himself from the start as a finished product. What you see is what you get. He had no interest or ambition to grow, change, or improve. He was already made, complete from the start. Therefore the Torah describes Esav as a “man who knows hunting, a man of the field.” He remains a primitive, boorish man who spent his days among the animals, doing what animals do – hunting in the field.

Yaakov’s name reflects the exact opposite quality, the insatiable appetite for growth and improvement. The root of Yaakov’s name is “akeiv,” or “heel.” When we walk, the heel is the first part of the foot that touches the ground. It represents the beginning, the first step, with much to follow. Akeiv means the beginning of a process with much greater things to come as in the expression, “ikvesa de-Meshicha, heel of the Messianic Era.”

Esav and Yaakov are twins who enter the world with the same DNA, the same “nature,” but who bring contrasting attitudes towards their “nurture.” Esav is satisfied with who he is from the start while Yaakov feels entering the world is just the first of many steps and journeys to come.

Indeed, while Esav is spiritually stagnant, remains immature and undeveloped, Yaakov spends his life struggling, wrestling and thereby growing. He overcomes his shy nature to assert himself, first by obtaining the birthright and then collecting on it by going entirely against his nature and tricking his father into giving him a blessing. Later, before his reunion with Esav, we will read of his encounter with the angel with whom he wrestles the entire evening and triumphs. The shy, passive yeshiva bochur who is characterized as sitting learning diligently in the tent, emerges the strong, dynamic, assertive patriarch and leader who is among the greatest role models of our people.

Esav chooses to remain "complete" – stagnant, but Yaakov puts one foot in front of the other, walks, jogs and ultimately runs to his destiny as Yisrael. No matter what our nature, we are not finished products. We can nurture ourselves to grow, improve, and change in all areas of our lives.

Jack and Oskar did not leave legacies based on the “natures” they shared in common like sneezing loudly or by the way they walked. Because of how they were nurtured, Jack left a legacy of having been an officer in the Israeli Navy while Oskar left of a legacy of having been an enthusiastic member of the Nazi youth.

We all have natures that predispose us, but through the way we nurture our lives, ultimately, we can choose who we are and the legacy we leave.