Apart from the Bible not saying much about the dead watching except from a vague

Hebrews 12:1 ESV

Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us

The idea of people looking down - while could be argued for in this verse - is moreso a human invention than scriptural in the case of Christianity. But the Roman Catholic Catechisms may have something to say about it