Jessica Chastain and Jennifer Lawrence just rocked them at the SAG Awards, models at the Monique Lhuillier and Moschino Spring 2013 Fashion Week shows bounded down in the catwalk in them, and Amanda Seyfried can’t get enough of them.We’re talking about mermaid waves—or the loose curls that fall glamorously down your back that stylists are heralding as “the new beach wave.”“It’s like mermaids are the new vampires!” says celebrity stylist Larry Sims, who tends to the locks of Eva Longoria and Kerry Washington. “Mermaid waves differ from beach waves in that they’re more polished and glamorous, with a distinct Hollywood feel,” he adds.MORE: Considering Bangs? Read This First.What’s more, experts say all this mermaid hair-wavin’ amplifies attraction. “Every strand of hair has a blood supply, and reflects what’s going on in the body,” says Nancy Etcoff, Ph.D., psychologist at Harvard Medical School and author of “Survival of the Prettiest: The Science of Beauty.” Wavy texture makes hair look naturally thicker and more voluminous, which we subconsciously take to mean that the wearer has a more robust supply of nutrients, making her more sexually attractive.If you want to get in on the action, the good news is that you can achieve mermaid waves with or without heat. Silky strands are essential, so use your favorite deep conditioner in the shower, or leave-in treatment once you get out. Then apply a waving spray to towel-dried strands (We like göt2be Beach Trippin’ Salt Infusion Waving Spray, $5.99 at drugstores in February.)MORE: The Psychology of HairBlow-dry hair if you’d like to use heat. Then wrap small inch-wide sections around a conical curler, brushing gently through the sections once finished to soften the style, advises Sims. Or as a natural alternative, divide hair into at least two sections and braid each one. Allow the braids to air-dry, ideally overnight. Then take out your braids, gently brush through, and show off your slamming new waves.