As a reproductive endocrinologist (and, therefore, a supposed expert on heredity), I’m often asked how much of a child’s development and ultimate personality is a result of genetics (nature) and how much is a result of its environment (nurture). Typically, this question arises when dealing with patients contemplating using donor sperm or donor egg.
I don’t have the answer to this question; it’s one I, myself, have spent much time considering. I’m one of five children and I have four children of my own and, so far, three grandchildren. Though the environment and the genetics of my siblings and and my children doesn’t appear to be so different, each of us has developed unique characters and personalities. Some are significantly different.
I think the nature vs. nuture question is like a Jackson Pollack painting. When you raise a child, different colors of nature and nurture are tossed randomly up in the air and what we call “life” dresses the canvas below. Sometimes the picture it creates is breathtakingly beautiful and other times you wish you could start with a new canvas.
Now, if you are a conscientious parent, then you are most careful about how and what colors of nurture you toss. With nature however, even with that which comes from you, there is no control.
So, I tell my patients who are screening donors and are so concerned that their donor has a particular color hair, eye color or even personality type, that they are putting too much faith in just one can of paint that they get to choose to toss up in the air. People with blue eyes and blonde hair have other colors from ancestors that randomly did not appear on their body. But their gametes contain them and these cans of paint will potentially have more impact on the canvas that the blue eyes and blonde hair that the recipient is hoping for.
The characteristics I prefer in a donor are healthy with good odds for successful conception and a generally appropriate mix of physical and behavioral characteristics to match the recipient.
Then I pray for G-d’s blessing.