E.O. Wilson, the biologist, theorist, and sometimes-novelist, has pioneered entire fields of study in his six-decade career. Back in 1975, Wilson popularized the theory of sociobiology: the idea that evolution and genetics shape human behavior. Wilson’s new book, "The Social Conquest of Earth" tackles this subject and through one simple question: how did altruism evolve in species like human and ants, when so few species are altruistic?

The National Kidney Registry called it "Chain 124." It began last August and lasted through December, linking 60 lives forever in the longest-ever chain of kidney transplants.  Through the cooperation of seventeen hospitals in eleven states, it connected 30 people who needed a kidney with 30 people willing to give up an organ to a complete stranger. Transplant chains like this are rare, but computer models suggest thousands more transplants could be made each year if there were a national databank of willing donors and recipients — and if more Americans knew about such programs.

It’s the season of giving, when we’re all told that it’s better to give than receive. But if so, why don’t we all give to charities? And what would motivate us to give more? These are questions that Stephanie Brown explores. Brown, an Associate Professor of Medical Humanities, Compassionate Care, and Bioethics at Stony Brook University, has developed theories on why people give, and why they don’t.

At 57 years old, computer consultant Harry Kiernan is one of the few living people to have donated multiple organs. So far he’s donated one kidney, part of his liver, and is currently waiting to become a bone marrow donor. What’s more, Harry has given each of his organs to complete strangers. Harry tells us how being with his wife Denise as she died of chronic progressive multiple sclerosis 12 years ago motivated him to give all that he could to improve the lives anyone he could: even people he didn't know.

People (and economists) have long thought that humans have a basic inclination toward altruism: toward helping one another without thinking of a reward. Stephen Dubner, co-author of "SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance" tells the story of how this was called into question and how studies complicate the picture of what motivates human beings.