In 1997, amid a swell in public attention towards disability rights, Mattel decided to release a Barbie doll that used a wheelchair. They called the doll “Share A Smile Becky,” and it looked like Becky would be a win both for Mattel and for disability activists, who hoped the doll could teach the public a thing or two about inclusiveness. But a major design flaw caused Becky to have quite the opposite effect.