Firstborn
I came across this just now, because another Jewish grapevine in my entire lifetime of 83 years was that the Hebrew Bible's HaSekhel HaYashar was to completely eliminate Human Sacrifice. I haven't read the history in the Wikipedia yet because I decided to use that keyword in the Virtual Jewish Library first.
So this distraction was so wonderful, thought I'd share it here. It's very 21st Century. First-born means a lot to me as a Mom. The first-born is the educator of motherhood, be it boy or girl. My older daughter when she came home from school at 7YO said to me: I'm glad Gene got born before me. I can get away with things that Marlene can't. I understood her perfectly. Marlene's family down the street was Jewish. They had two girls and one boy. Girls feel the responsibility ethically and morally more than boys do. That's my experience. Boys play games just naturally. That's my experience.
Another way of looking at it is this. Until the 19th Amendment in 1920 (I was born 1929), it was the oldest girl who took care of the children while mom kept a kosher house, a full-time job. That's how my mom was raised, by her oldest sister. Most of my own friends, the girls worked so their brothers could afford to go to college. Being poor, I was just plain lucky all my life, that my homophobic single-parent mom treated my brother and me equally economically so that I could spend my work money sending me to college. Very unusual in my day even with a working father in the house. That's why I'm grateful for the way the casino of existence in the USA happened to me.