In March 2015, astronaut Scott Kelly embarked on a one-year stay aboard the International Space Station, while his identical twin brother Mark Kelly, a retired astronaut, remained on planet Earth. This remarkable event—accompanied by a frenzy of media attention—created a degree of separation between twins that scientists could previously only imagine. For science journalists and their readers, the Kelly twin astronauts were like a dream come true, a perfect marriage between popular fascination with twins and Americans’ boundless enthusiasm for space travel. Attention-grabbing headlines like “Meet the twins unlocking the secrets of space”, “Nature vs. Nurture vs. NASA”, and “NASA twins to embark on year-long space experiment” began to appear in the news. Friends and colleagues were quick to forward these stories to me, knowing of my personal (I’m an identical twin) and professional (I’m an anthropologist who studies twin researchers) interest in twins. Scientific research on twins has a long history, so as I read about the plans for experimentation on the Kelly twins, there was much that was familiar to me. In a way, the twin-in-space and twin-on-earth scenario is a logical conclusion of long-standing scientific fantasies about twins and their power to reveal the hidden workings of nature and nurture. Interestingly, however, by the time it became possible to realize this older vision of twin research, the life sciences had entered the molecular era, with new methodologies and technologies threatening to replace the classical twin study. So, we might ask—how did we end up with this improbable study of twin astronauts? (read more...)