Multigenerational households are growing in the United States, according to a 2010 study by the Pew Foundation. Such households were common in the early twentieth century, then they declined, reaching a relative low point around 1980. They have been rising since then, showing a distinct uptick with the recent recession. In a culture that emphasizes independence, multigenerational households generally expand out of necessity, providing further evidence that times are tough. These trends will affect the retirements of millions of Americans.