Super-nerds have transformed Silicon Valley: now they're transforming philanthropy.
The Chronicle of Philanthropy's 2012 list of Top 50 Most Generous Donors shows that three of the top five donors are under 40 - by far the largest number of young donors at the top ever. They gave close to $1 billion in 2012.
The top-ranked young donor was Facebook founder Mark Zuckerberg and his wife Priscilla Chan, who gave $498.8 million to the Silicon Valley Foundation. Close behind was hedge-funder John Arnold and his wife, Laura, who gave $251.2 million to Laura and John Arnold Foundation, which funds education and criminal-justice issues, and $172.2 million to other nonprofits, for a total of more than $423 million.
(Read more: Are the Rich Less Charitable Than the Middle Class?)
Rounding out the top five was Google founder Sergey Brin and his wife, Anne Wojcicki, who gave some $190 million to the Brin Wojcicki Foundation, which funds medical research and other causes, the remainder of their $222 million total to the Michael J. Fox Foundation for Parkinson's Research. (Read More Below the Video.)
In total, the top 50 donors gave $7.4 billion in total gifts this year - with the top five alone accounting for more than $4.5 billion. The list is just for new commitments, so it doesn't include money given by Warren Buffett and Bill Gates as part of their previous charitable commitments. Yet Buffett topped the list with $3 billion in new commitments to his children's charities.
Stacy Palmer, editor of the Chronicle of Philanthropy, said the rise of young, tech givers signals the emergence "nerd philanthropy," where newly rich tech geeks channel their giving dollars to science, technology and data solutions to solve the world's problems, rather than just building hospital wings or writing checks to the Red Cross.
"There this real excitement about what science can do," she said. "It's not just a gift to a hospital, but a gift aimed at trying to support research."
(Read more: Are Brits Less Charitable Than Americans?)
Nerd philanthropists like to be able to measure the impacts of their giving. They take a lower-profile approach, sometimes refusing to make their charitable projects public. Sergey Brin, for instance, has been tight-lipped about much of his philanthropy - a stark contrast to philanthropists who like their names on plaques and announcements.
Nerd philanthropy also applies to older tech givers of course. Paul Allen's $309 million in giving in 2012 included funding for brain research. And Bill Gates is widely considered to be the father of nerd philanthropy.
But as tech fortunes grow, nerd philanthropy is also expected to rise and possibly influence other givers.
"This shows that the future of philanthropy is strong even given the difficult economy," Palmer said.More From CNBC
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