More than just about any other animal, we like to decorate ourselves. Our coverings (clothes) are more than just functional to us. The selection of style, color, and even fabric is used to send messages about who we are. Clothes are used to signal group membership, and t-shirts can be used as walking billboards for companies or causes. These selections (either by free will or by dress codes) are designed by cultural norms to express ideas of maturity, creativity, or individuality.