Just as the year came to an end, we celebrated the feast of the Holy Family on Dec. 30. We remember that the church celebrates the feast right after Christmas. After celebrating Christmas, the feast of the Incarnation, when the Son of God became human, we celebrate the next Sunday that the Incarnation happened in an actual historical family. The assumption is that just as even the Son of God, Jesus, came from a family, so do we. Having a family means being a human being, and vice versa. It’s quite a wonderful claim to celebrate. But then as we begin the New Year, the church celebrates Mary the Mother of God on Jan. 1. The church begins and ends the year with images of family. Still, this is not a time for correlating: we don’t compare our mothers to Mary, nor our fathers to Joseph, nor ourselves to Jesus. Rather we celebrate this insight: that being human means having a family. That’s a message not only for the end of the year, but the beginning of the year as well. The Gospel reading on the feast of the Holy Family got me thinking about a particular dimension of family life that rarely gets considered. Praying over Luke 2:41-52, where the 12-year-old Jesus stays behind in the Temple, I thought, what would it have been like if Jesus had had siblings? For instance, if Jesus had had an older sibling, what would she or he have said to him after having to leave the caravan, return to Jerusalem, spend three days of looking for him, and then hear him say to his mother: “Why were you searching for me? Didn’t you know I had to be in my Father’s house?” Can you imagine what the older sibling might have said to him after the parents left? What if he had had a younger sibling? Can you imagine what a younger one might have said after the parents left? After the parents leave, that’s when siblings are most like siblings. Left to one another, siblings are most like themselves. I know that some of you do not have siblings. But bear with me. In 2011, only 10 percent of U.S. households with children had an only child. Today, 20 percent do. But when it comes to the Catholic Church talking about families, often it talks about a parent’s relationship with her or his spouse, and with children and a child’s relationship with the parents. Rarely is there much preaching on the family that includes siblings. And as an ethicist, I also realized that there’s very little ethical reflection on being a sibling. Friends, yes; siblings, not much. For instance, in the Bible we see friends like David and Jonathan, Ruth and Naomi, Jesus with Mary, Martha and Lazarus or Jesus and John the beloved disciple. You turn to siblings, there’s Cain and Abel or the notorious brothers of Joseph. Similarly, from Plato and Aristotle to St. Thomas Aquinas and St. Aelred, great thinkers have written about friendship, but little on siblings. This lack of information is significant, I think. The type of friend I was at 12 years of age is not the one I am today. But what about the type of sibling I was at 12? Does our understanding of being a sibling mature like that of a friend? Of course, there’s a difference in the comparison. My friends today don’t know what I was like at 12. My siblings do. So I leave you with this. If we have been taught through a variety of ways what it means to be a good friend, what measure do we use to see whether we are a good sibling? What resources are there for becoming a better sibling? Are there public role models, like the Kennedy siblings or the Bush brothers? Or, after the parents leave, do we just start acting the same way we did when we were 12 years old? I’d be most grateful if you’d send your ideas to me at email@example.com.