They have the power to add a pop of color to an otherwise plain outfit, tame unruly hairstyles, or even to add a layer of warmth. Scarves really began to soar in popularity in the 20 th century. Prior to that, women often wore shawls essentially larger versions of scarves. These were most popular during the 19 th century, and dipped in and out of favor according to changes in popular silhouette. Mary Crawley in Downton Abbey wears a skinny scarf knotted to the side of her neck.