The gerontological explosion will redesign the family structure in this century. The proportion of Americans who are age 60 with at least one parent still alive has risen nearly 45% since the beginning of the twentieth century. In 1960, 14% of Americans age 50 still had both parents living; in 2000, that figure swelled to 27%. As a result, more children will get to know their great-grandparents, as the four-generation family becomes more common. There will be more responsibilities assumed for taking care of older relatives: In 1997, more than 20-25 million Americans provided or administered care for older family members, and that number is expected to rise sharply in the coming years.