The upper part of the trapezius muscle is the primary target of the shoulder shrug. The trapezius is a triangular muscle that makes up the upper back, running from the back of the neck and down along the spine, lying over the shoulder blades.
In general terms, sex refers to the biological differences between males and females, such as the genitalia and genetic differences. Gender is more difficult to define but can refer to the role of a male or female in society (gender role), or an individual's concept of themselves (gender identity).
Men and women differ in the way they think, feel, act, and talk. In fact, one of the most striking differences between the sexes is the unique ways that men and women communicate. In recent years, the communication styles of men and women have been studied scientifically.