published in the Baltimore Jewish Times Parsha Toldot
To what extent do genetics determine human behavior? How much influence does the child-raising environment exert on a person’s development? DNA testing can trace the inheritance of physical traits, such as blue eyes or dark hair—but what about social qualities? Will the child grow up to be gentle, deceitful, successful, and socially defiant? The intriguing question of "nature vs. nurture" is brought to life in this week's parsha, Toldot. How does the Torah interpret the interplay between lineage and family dynamics?
The dramatic biblical scenario begins before the birth of Rivka’s (Rebecca’s) twins, Yaakov and Esav, when polarity develops in utero. Rivka has a revelation by G-d about the twins' opposing natures and their respective ascents to greatness: "Two nations are in thy womb… one people shall be stronger than the other people; and the elder shall serve the younger." (Bereishit 25:23)
According to the Midrash, when the pregnant Rivka would pass a Yeshiva (house of Jewish learning), Yaakov would kick with joy, but when she would walk near a place of idolatry, Esav would thrash about. At their birth, Esav emerges first from the womb, all ruddy and hirsute. The fair-skinned Yaakov follows, clinging at Esav's heel. As he grows, Esav becomes a trapper and hunter, Yaakov a man of learning. Twin brothers could not be any more dissimilar. We see clearly here that personality traits as well as physical differences begin at conception.
The story focuses on the "generations" (Toldot) and the importance of family position and genetic heritage on the development of children. In the parsha, we read that Yitzchak, the father of Yaakov and Esav, must stay in the holy land of his father Avraham. Yaakov buys Esav's birthright and in exchange gives a famished Esav, just back from the hunt, a bowl of lentils. Through a ruse designed by Rivka, Yaakov receives the blessing from Yitzchak, meant for Esav. Esav vows revenge and Yaakov flees to live with Rivka’s brother, Lavan. Esav marries Canaanite women, and Yaakov is tricked by Lavan into marrying his older daughter Leah; Yaakov then marries her sister Rachel, whom he loves, seven years later. Yaakov fathers twelve sons; each rises to become tribal leaders.
Twin brothers, with shared DNA, raised in the same household, develop into two divergent personalities with radically different outcomes.
Ironically, the wild Esav and, generations later, the noble King David, were both born with red complexions. After G-d reassured Samuel that David had "beautiful eyes" (thus differentiating him from Esav) David overcame this apparent similarity and rose to greatness as a warrior and leader. Rivka’s father, Bethuel, and brother Lavan, were both deceitful, yet she overcame both environmental and inherited propensities to become a righteous woman. In contrast, Esav departed from his holy background.
Scientific and philosophical theories about the relative influence of nature and nurture abound. Secular Modern theorist John Locke believed everyone started out as a blank slate, a tabula rasa. Psychologist B.F. Skinner held that a person’s behavior is shaped by negative and positive stimuli in the environment. Professor Ronald Dworkin showed evidence that embryonic growth influences the development of genes. Zoologist Konrad Lorenz found that animal behavior was "imprinted" immediately after birth. Psychiatrist Karl Jung theorized that shared traits in all human beings were found in the collective unconscious. Each viewpoint sheds a bit of light and harmonizes with the truth found in Torah.
Choices have consequences. Rather than blame "human nature" for poor judgment, we can control our tendencies with free will. It says in Pirkei Avot: "Know from whence you come and whither you are going…" It is not enough to "live and let live;" we must consider the far-reaching effects of our decisions. The future of humanity as a whole is determined by the personal choices—for better or worse—made by individuals.
Many great leaders have risen from humble beginnings. Every person has the power to change his or her apparent destiny for good or bad. Environment is often a key factor for our quality of life, but certainly not the determining one; the ultimate choice always remains ours alone. Each one of us is a combination of our genealogical history, our upbringing, and free will; our potential is unlimited. Our choices set an example and imprint for generations to follow. May we choose our path with wisdom and fulfill our greatest promise, leaving a lasting legacy for our children. Shabbat Shalom.
Rabbi Weisblum is the spiritual leader of Congregation Kneseth Israel in Annapolis. He is a renowned musical composer and author of the popular books Table Talk:Biblical Questions and Answers and Ruth Talk:Questions and Answers on the Book of Ruth.