Even though, earlier, the Iroquois typically had only three or so children per family, these longhouses were built for 80 to 120 people. A woman would have had to live to be 60 years old to fill these large longhouses with her own family. The evidence suggests that something was going on politically and socially in order to manage a denser population, a larger local population, and a larger household. After 1635, disease disrupted families so much that fictive kinship was invented to allow the repackaging of people into Ionghouses once again. New relationships were created to regroup the half-destroyed population, but these seventeenth century innovations are long forgotten.
Oral tradition says little of the change.
Archeology is the only source of such understanding. Archeology reveals other details. The width of the longhouse and the length of each compartment was three fathoms. Storage compartments for corn could be found at either end. In the Mohawk Valley each Ionghouse also had a large post that was apparently moved from place to place, not abandoned to rot in place.