be less caring and/or more violent if there were no Thanksgiving and Christmas celebrations?
The problem is not Christians (Christmas) or Americans (Thanksgiving)... the problem is radical Islam. (Since you're asking about the world).
Does the spirit of Thanksgiving and/or Christmas affect you personally or is it just holidays from work, football, good food and drink, football, gifts?
On a personal level, the holidays do not make me a more or less caring person.I act and behave the same way all year long, not just the last 30+ days.