Some people believe holidays change people, but I think they’re far more likely to bring out what’s already inside — for good or for bad. Holidays that center around family frequently tell me who someone really is.

I pay more attention to children than most adults do. I watch families. I talk with children when I can. I take them seriously and I play with them frivolously. I love their world and I love the ways in which they can change how I see my own world.

That’s never more true than around Christmas.

Whether children are from families which are religious or not, there seems to be something magical that takes over around this time. (I presume the same is true in cultures where there are other religious and cultural traditions, but my experience is in an American Christian cultural context.)

Something I experience in these children at this time changes me — or at least brings out something in a stronger way that’s always there.

I watch happy children singing Christmas songs for parents and grandparents. I watch their eyes light up as they talk about stories they’ve learned, whether it’s about Jesus or Santa or the Grinch. Some of the excitement is about what they hope to receive, but there’s definitely something more.

It’s as though they experience a certain kind of magic in this season — and it rubs off on some of the lucky ones around them who pay attention.

Nothing makes me want children of my own the way this season does. I can’t rationally explain that. In fact, I can tell you why the rational thing is to avoid having children. They’re expensive. They’re a lot of work. They put a lot of things in your life on hold (if you spend enough time with them). And no matter how you raise your children, it’s possible you’ll end up with your heart broken — and you might not even be able to understand why, even when it’s clearly explained to you.

But something in me needs to create life and raise happy, healthy children — and I have very specific instinctive ideas about the sort of woman I have to reproduce with. I can’t explain where those strong convictions came from. I can’t justify that they’re right. I certainly can’t force them to become reality.

I just know — in the most secret part of my heart — what is right and what ought to be. There are times when what you know is right trumps all reason and all other logical desires and conclusion.

Around this time of year, the urge to make this a reality becomes more like an obsession. I’m driven to do whatever is necessary to build the reality I see so clearly in those images in my heart.

Maybe I’m not alone in this. Just today, I ran across a journal article that shows people across 129 countries (where data are available) become more interested in sex and reproduction at the times of their culture’s equivalent of our Christmas season. In a paper called “Human Sexual Cycles are Driven by Culture and Match Collective Moods,” five researchers show in dry statistical language that this is true.

On the surface, it’s about sex, but on a deeper level, it’s really about sex as a means of expressing a desire to fulfill a genetic and cultural imperative to reproduce. In language that’s not so dry and statistical, it really means there’s something about this time of year that makes us even more likely to want to become what we already want to be — and what I want is to be a husband to the right woman and father of our children.

This season makes some people bigger jerks than usual. It makes other people more greedy than ever. It makes some people put on airs to try to impress other people with their wealth and social position. It makes some people eager to drink alcohol and consume other recreational drugs — in attempts to escape what they are or to find some sort of pleasure they can’t find in their sober states.

Whatever people are — whatever people want — they seem to become that much more of that right now.

This season fills me with the longing for children — and all the things which come with that in my mind’s eye.

This isn’t a sudden revelation for me and it’s not news to anyone who knows me well. But it’s not a rational desire or goal. It’s not like a desire for a nice house or better clothes or shiny gadgets. It’s more like the desire for air or food or water.

It’s a fierce desire to fulfill one of the key reasons I’m alive.

Many people have no such desire to reproduce. And even some of the ones who want children in a theoretical sense have no interest in doing the difficult work of nurturing them in healthy ways once they’re born. I have no objection to people not having children. In fact, many children would be better off without being born to certain parents. (The most important decision you ever make for your children is who the other parent will be — and many people fail to take that decision seriously enough.)

I’m not saying everybody ought to have kids. I’m just saying that I need children. Something in my genes drives me toward that — and the study I read today makes it clear that culture drives others to feel this way, too.

On this Christmas Eve, I know plenty of people who are enjoying spending time with their children, delighting in the wonder that these young children are experiencing. I envy them. Now that stores and restaurants are closed — and church services are finished for the evening — I’m at home alone with a dog and a bunch of cats.

I love my little zoo, but they can’t take the place of what both genetics and culture are driving me toward. I want this every single day of the year, but at this time above all, I need to be a husband and father.

That’s the part of me that gets magnified right now, because it’s who I am in my heart.

Merry Christmas to everybody, but especially those children who are experiencing the magic which I long to experience with kids of my own.