Even though the overall amount of charitable giving is down from last year among America’s top 50 donors, for the first time ever, three young couples are among the top five most generous. According to the new list from The Chronicle of Philanthropy, Mark Zuckerberg and his wife Priscilla Chan fall behind only Warren Buffet in the amount of money they gave away in 2012. Also in the top five are two other couples who are under the age of 40: Texas billionaires John and Laura Arnold (both 38) and Google’s Sergey Brin and his wife Anne Wojcicki (both 39) each gave hundreds of millions …
