For Jennifer Lawrence, Kristen Stewart and Taylor Swift, the swoosh of glossy waves favoured by Middleton/Kim Sears/Victoria's Secret Angels (so last Wimbledon, so last week) has been swept aside. It's now all about mom hair: short, shaggy crops of indeterminate hue to match your handbag, worn in a vague side-parting. Like its sartorial counterpart, the mom jean, mom hair comes from a place of love, which gently pokes fun at an older generation while also making the modern wearer look slightly transgressive. We say moms never looked so sassy.