'Sometimes, 1+1 = changing the world. Cathy Newman's witty, warm history on the power of determined couples will make you look at your relationship and wonder, "Could we be doing more this weekend than just going to IKEA?"' CAITLIN MORAN Throughout history, collaboration has fuelled greatness. From rivals pressuring each other forwards to friends combining their talents, it's clear: often two heads are better than one. In It Takes Two, Cathy Newman rewrites the history books to expose this strange power of two - the reason Holmes and Watson need to come as a pair, and Apple could not have been started by Steve Jobs alone. Bringing together an extraordinary range of stories from around the world, Newman shows how double acts have relied on each other, how minds have married to usher in miraculous discoveries, and how those we think of as lone geniuses often did not work solo. How did William and Ellen Craft work together to pull off a perilous cross-country escape from slavery? How did the queer artists Marcel Moore and Claude Cahun become icons of the surrealist movement, then heroines of the resistance during WW2? How do today's most powerful couples - from Beyonce and Jay-Z to Bill and Melinda Gates - negotiate coupledom and individual achievement in the spotlight? Vibrant, feminist and unexpected, this brilliant history shows the value of friction, obsession, difference and trust when it comes to progress - and retrieves the work of many who have been forgotten, asking why certain collaborators are so often left out of the narrative.