The modern field of psychology is in part defined by one such partnership: Daniel Kahneman and Amos Tversky. In deep collaboration, the two discovered foundational insights about the mind and, in part, founded the field of behavioral economics. They became one of the greatest partnerships in the history of science, explains Michael Lewis in the book The Undoing Project: A Friendship That Changed Our Minds. Kahneman detailed that magic to Lewis: “We were quicker in understanding each other than we were in understanding ourselves.…When one of us would say something that was off the wall, the other would search for the virtue in it. We would finish each other’s sentences and frequently did. But we also kept surprising each other. It still gives me goose bumps.”Kahneman and Tversky’s partnership was a tumultuous one, leading to a deep rupture. Before Tversky’s death, the two had a reconciliation of sorts, and in 2002, Kahneman was awarded the Nobel Prize in Economic Sciences. It was, in his words, a “joint prize.” In his Nobel Prize statement, Kahneman wrote: “Amos and I shared the wonder of together owning a goose that could lay golden eggs—a joint mind that was better than our separate minds.”Other world-famous duos include Francis Crick and James Watson, whose contentious collaboration (along with the work of Rosalind Franklin and others) led to the ground-breaking discovery of the double-helix structure of DNA. John Lennon and Paul McCartney’s songwriting partnership generated some of the greatest, most enduring music of all time. The team of Rodgers and Hammerstein reinvented Broadway. Writer Robert Caro and editor Robert Gottlieb’s beautiful 50-year partnership produced The Power Broker and the Lyndon Johnson biographies. Comedy duo Tina Fey and Amy Poehler began in the Chicago improv scene before skyrocketing to fame on Saturday Night Live and each creating a smash-hit sitcom. In the business world, Larry Page and Sergey Brin created Google; Ben and Jerry created Half Baked.And then there’s the double duo—collaborators who are also couples. Physics giants Marie Curie and Pierre Curie transformed science and medicine through their study of radioactivity. Philosophers Simone de Beauvoir and Jean-Paul Sartre produced influential theory and literature. Neuroscientists Stephanie Cacioppo and John Cacioppo researched love while being very much in love. One figure who falls into both categories is the eminent psychologist John Gottman, who says that he has been blessed with two deep collaborations. One is with University of California, Berkeley professor Robert Levenson, with whom he transformed the study of love into a remarkably accurate predictive science. The other is his wife of nearly 40 years, clinician Julie Schwartz Gottman, with whom he developed powerful therapeutic techniques. Both partnerships are akin to complementary puzzle pieces that fit together to form something magical.