Question

Before World War II, the United States had no interstate highway system, and traveling to different parts of the country was difficult. This means that ________ must have been even more important in determining mate selection.

Answer 1

Propinquity (or proximity) must have been more important in determining mate selection before World War II and the creation of the interstate highway system.

Propinquity is a sociological term. It means nearness, either in terms of space (proximity), time (contemporaneity), or blood (kinship). Here, we are looking at the space aspect, because the lack of interstate highways meant that people were a lot less mobile. If they were more likely to spend their lives in the same place, then they would probably choose a spouse who was "propinquant," that is, who lived in the same area.