"Growing Old in America: Expectations vs. Reality" Pew Research Center, Washington, D.C. (JUNE 29, 2009) 
Family Relationships - Page 10
Staying in Touch with the Kids.
Nearly nine-in-ten adults (87%) ages 65 and older have children. Of this group, just over half are in contact with a son or daughter every day, and an additional 40% are in contact with at least one child—either in person, by phone or by email—at least once a week. Mothers and daughters are in the most frequent contact; fathers and daughters the least. Sons fall in the middle, and they keep in touch with older mothers and fathers at equal rates.