www.pbs.org/humanspark At Oxford University, Alan Alda finds out from Robin Dunbar how human social networks compare to those of chimps, and at Yale University, watches babies as young as three months old pick cooperative puppets over those that won't play. In "The Human Spark," Alan Alda visits dozens of scientists on three continents -- and even undergoes an examination of his own brain -- to find the answer to one question: What makes us human? Coming to PBS over three Wednesdays: January 6, 13, and 20, 2010 (check local listings). Learn more, and tell us what YOU think makes us human at www.pbs.org/humanspark