For this week’s cover story, I trekked to a hillside village in the Philippines, interviewed refugees in Uganda and visited a crowded Bangladeshi hospital in the middle of an outbreak of bacterial disease. I was reporting on the cheapest, simplest way to raise the world’s IQ. It is to tackle malnutrition, which can severely hinder brain development, especially in the first 1,000 days after conception. Sondre Solstad, one of our data whizzes, helped to illustrate the gravity of this problem. In Asia and Africa I heard how people are trying to fix it. Among the most inspiring stories were those from scientists who are seeking to harness benign gut bacteria to help people better absorb nutrients. Overall, it was one of the most hopeful stories I’ve ever reported. To make the next generation smarter, we need to feed babies better.