For many people across the nation, both Thanksgiving and Christmas are secular holidays, highly valued because of family traditions that symbolize love and affection, says UC Davis folklorist Jay Mechling.

Families, ethnic groups and even whole communities invent traditions through foods, events and stories that celebrate our roots. And many who don't celebrate Christmas have created parallel winter celebrations with spiritual and ethnic ties, such as Chanukah and Kwanzaa, to offer comparable symbolic traditions to their families, says Mechling, a professor of American studies.

"People use traditions from their own families and communities to make the holidays meaningful to them," Mechling says. "For Christmas, this can be a tradition of when presents are opened; for Thanksgiving, much of the traditions deal with who makes the various dishes."

Many people who aren't practicing Christians, including those from other religions, celebrate Christmas as a family holiday, Mechling says.

He says the celebration predates Christians, pointing to the many Norse symbols that dominate holiday: the German Christmas tree and Yule logs introduced to Victorian England by the German Prince Albert in the mid 1800s. St. Nicholas, a real bishop, changed into the Santa Claus drawn by cartoonist Thomas Nast.

"Christmas, in particular, has become such an important holiday because Christians were able to connect the birth of Christ with powerful winter solstice symbols and rituals shared for centuries before," Mechling says. "The holiday touches the fundamental seasonal rhythms symbolism around fire and hearth."