The Christmas effect on societal concern

In terms of Google search volume, all nine of the following items typically reach their low points for the year during the holiday season:

• business, education, work
• environment, abortion, poverty
• President, Congress, politics

Maybe, you think, there's a universal drop in search volume around Christmas.  However, the holiday effect is absent in these Google Trends:

• family, fun, television
• red, white, blue
• whiskey, scotch, bourbon

Perhaps further study would show the effect to be spurious, but I've searched enough for my satisfaction.  Maybe everyone already knows about this; it certainly makes intuitive sense, but it's interesting to see it in data.  Shall we call it "the Christmas effect on societal concern"?  Not very catchy, I admit, and possibly not sufficiently precise; any better ideas?

AMUSING UPDATE:  One possible use for the Christmas effect is to play "Spot the Controversial Issue".  Check out the trends for liquor, tobacco, and marijuana.  Two of the three suffer the Christmas effect (meaning, they are objects of societal concern), and one doesn't (quite the opposite, in fact); try to guess!