It does seem like there's something wrong with that data; I find it somewhat implausible that the average parent was only caring for their child for 1.7 hours a day in 1985; even if you assume that all of the tween and teens were free-range and only got an hour or two of parenting a day, little kids have always required nonstop attention to make sure that they're not actively dying.

Although... the infant mortality rate in the US has dropped by more than 50% since 1985, so who knows...