Debutante balls?
It seemed a bit out of place that the narrator described coming-out parties for the girls, and if I remember right, I think the narrator used the word "mansions." The Lisbons and the boys all seemed solidly middle-class. The father was a schoolteacher, and it seemed the mother was a homemaker (not unusual for early '70s). The neighborhood looked comfortable but the houses weren't that large, especially for the Lisbons, with all those kids.
Wouldn't debutante balls like that have been very unusual for middle-class Michigan in the early '70s?