Volunteering culture in the United States

In Webster Unabridged dictionary voluntary action is defined as the practice of one's time or talents for charitable, educational or other worthwhile activities. Also Voluntary action is an unpaid work except expenses and it does not mean just to help one's community, but what seems to be more important is that, voluntary action helps the person him/herself and can generate a sense of satisfaction and calmness in the individual.
Speaking about voluntary action, it is noteworthy to mention some of the benefits of voluntary action. First of all sense of self-satisfaction pushes the individual to participate in these kinds of activities. Secondly, it provides a space to open parts of the one's character that were unknown up to that point. But why the rate of voluntary action is considerable in the United States? Does it have anything to do with government, culture, religion, or….? Let's have a look on the rate and traits of individuals' participation in voluntary works.

% characteristics

23 Men
30.1 Women
28.3 whites
19.2 blacks
32.2 married
20.3 single
31.2 35-54
17.8 20s
18.5 Asians
13.9 Latinos
Volunteering in the United States, U.S. Bureau of Labor Statistics, September 2007
It seems that volunteering is declining in the United States, especially among teens. After so much research I realized that volunteering is popular not only in America but also in other countries as well. Especially after World War II some organizations began to exercise volunteering. For example in Asia, Africa and Latin America many people experienced that. But the most important impetuous behind volunteering is self-satisfaction and it doesn't have anything to do with religion or nationality or race. What is here questionable is that why in spite of the fact that Islam has always been a pro-volunteering religion, its adherents especially in Iran are not the most interested people to volunteering? I couldn’t find a persuasive answer to this question, but I think in spite of the ample willingness among Iranians, maybe economic daily life has so much preoccupied them that they prefer to do something financially rather than spiritually rewarding. I can only be hopeful that we practice Islamic lessons more eagerly and relive ourselves from repeated routines.