Last week my wife and I took our eighth-grade daughter to an open house at the local high school where students can specialize in visual and performing arts.

I was surprised to see, in the commercial-art classroom, a member of our high priests group.

I had known — once — that he was a teacher at one of the high schools, but not this one. More to the point, I didn't actually care what he did for a living. I did not know him by his job. I knew him by what he said in quorum meetings, who he was in the ward.

It's one of the great blessings of life in The Church of Jesus Christ of Latter-day Saints. The world labels people — men especially, but women, too, these days — by their careers. And that includes assumptions about how much money they make, how educated they are, and so on.

But in Mormon wards, we can forget all that. People "are" their callings, but because those change rather often, our real knowledge about them consists of how well and faithfully they do their callings, what they say and do in meetings, how often you run into them setting up or cleaning up after meetings.

The Mormon ward gives us a way to know each other.

A few years ago I read R.I.M. Dunbar's speculation on the reason human brains are so much bigger than those of the apes.

Part of his idea is that human speech developed as a way of grooming each other, as other primates do, only without using our hands, so we could do our work and interact socially at the same time.

But I had to chuckle when I got to his observation that brain size in primates correlates with the size of the ordinary social group. Comparing the brain size of intensely social primates like chimps and baboons with the size of the average troop, Dunbar determined that the optimum group size for humans should be about 150.

I laughed because he had just tagged the size of a typical Mormon ward. Outside of Utah, if you get much more than 150 in sacrament-meeting attendance, they start thinking about dividing your ward.

More than that, and you start to feel lost. It's just too many people to grasp all at once. It starts feeling like a bunch of strangers instead of a community you know.

When my wife and I lived in Utah, we saw first-hand how large wards — like large schools and large companies — can leave some members feeling like an extra. Unneeded. Anonymous. Lost.

Naturally, there's still a wide range of fluctuation. We remember the identities of a lot more people than just 150. But it's hard to be closely involved with more than that.