Atia
I suspect part of it is that mums tend to be around more in school, so more involved. Despite having meetings in the evening I can only remember 1 dad who came to a PTA meeting and if dh ever said he could go on a school trip the teachers were practically dancing a jog because they usually had to beg for one dad to go (for toilet trips). There was a waiting list for mums.
But with me and dh, he is far more relaxed about almost everything. I'm by far and away the most relaxed and sociable of my family, but his family is a whole step away from me.
He tends to go "oh they'll be fine..."
Whereas I worry about the same things I worried about for m, but can do less about it. Will they make friends? Will they cope with the work? What if something happens? etc.
I wouldn't he is less interested, just that he doesn't express it, he just assumes all the things will turn out fine.
My df was similar, dm was much more worried about the day to day (although df could get worked up about odd things. I remember well my first spring term, in the end of January mentioning I had a tutorial the other side of town at 7pm. "I hope you don't go out after dark" he said. "Never," I replied. He could work that one out if he needed to
)
But I know df was as interested, he just wasn't inclined to ask about day to day things.