Healthy, straight hair is like the perky, popular girl in high school—polished, shiny, effortlessly pretty and annoyingly enviable. Some hairstylists say that straight hair is the easiest hair type to manage.Natural characteristics: Healthy straight hair is known for its mirror-like shine. That’s because straight surfaces reflect more light. This hair type has little-to-no volume and doesn’t hold hairstyles, such as waves or curls from a curling iron, easily. Like most hair types, straight hair can be fine, medium-textured or thick and coarse.Although straight hair is believed to be less prone to spontaneous knotting, research shows that the opposite may be true. Case in point: A study published in the American Journal of Physics revealed that curly hair averages about three tangles per head while straight strands averages more than five tangles. According to the researchers, the angle at which two straight hairs bump into each other is the angle most likely to lead to tangling.The nitty gritty: Scientists don’t know why different hair types develop, but the shape of the hair follicle matters (yours is straight), as does the way hair proteins (keratin) are clustered in the hair shaft. Your type can change, so your straight locks may turn to waves later in life.Hair challenges: Lack of volume is a common lament of straight-haired gals, notes celebrity hair stylist Kristan Serafino. Globbing on hair products and a lack of layering in the haircut can lead to flat, ho-hum hair.Challenge accepted: Volumizing hair products give lifeless hair a much-needed lift, but slathering them on will only weigh your hair down. “The key to getting the best possible results is to use only one or two hair volumizing products,” says Serafino.A volumizing conditioner is a better choice than volumizing shampoo, since shampoo is not formulated to cling to the hair. Just be sure to avoid the roots and use a small amount of product. After blow drying the hair dry with a big round brush, apply a tiny dollop of volumizing mousse or hairspray on the roots of your hair. “Apply it with your head down, scrunching up the hair,” suggests Serafino.Overuse of deep conditioning treatments can leave build-up in the hair, causing tresses to fall flat. Instead, do a deep conditioning treatment once a week or every other week. “Use a clarifying shampoo once or twice a week to remove the build-up on the hair,” suggests Serafino.Best hair care ingredients:* Silicone helps make straight hair look incredibly sleek, smooth and shiny.* Meadowfoam is a natural ingredient that penetrates the cuticle to hydrate the hair without leaving it lifeless or greasy.