Social significance of the eyebrows and periorbital complex.

The eyebrow is simple to regard, but complicated to understand. Over the centuries it has been used as an indicator of social status, gender, and level of authority. In differing societies its descent and thinning with time have made it an important benchmark of the aging process. The brow is higher in the younger woman, but because of the loss of periorbital bone and fat starting in early middle age in women, the brow tends to descend, giving a tired, depressed, or anxious appearance. The brow in men is usually more resistant to downward movement until they are in their fifties. As a result, a whole industry has grown up around such varied techniques as plucking and redrawing, or gluing or tattooing on a replacement. In earlier centuries, the shaven forehead and almost absent brow were seen as a symbol of sexual purity. In the modern age, the brow is seen as an important part of facial recognition technology and is valuable in aspects of security and monitoring.