THREE KEY FACTS: Emil Dalgaard Christensen’s study found 1-year-olds with siblings pick up a useful range of bacteria that protects them from illnesses. Only-children scored 9 vocabulary points higher than those with siblings in Bill McKibben’s research. One in four Roman babies died before they were a year old.
Tom Payne writes for The Telegraph. OPINION No pity or judgment here please, the research shows only-children are not so different — apart from a few benefits..