That's not universally true. US homes in warm climates had high ceilings until the advent of central climate control. Homes in cold areas tended to have low ceilings to keep the warm air where it was most useful: at the level of the occupants. Eight foot ceilings are very common in tract homes built between the introduction of air conditioning and the start of the McMansion trend in the 1990s. Common areas with higher ceilings are not rare in newer homes.