More boys are dreaming of becoming dancers than firefighters or policemen, as reality shows such as Britain’s Got Talent and Strictly Come Dancing trigger a cultural shift. A survey found dancing was the third most popular career choice of boys aged between two and 12—just behind doctor in first place and footballers in second. More boys—8 percent—want to be dancers than girls—5 percent. Some 7 percent of girls would rather be a footballer than pursue a more traditional female career, such as a nursing. The research by Mothercare and Save the Children shows the impression left on the kids of...