Sporting leather pants or trousers, much more often than not, especially those tight ones, is simply a fashion statement. Wearing tight leather clothing, particularly for pants, often emits a sense of style and strength. 

Most of rockers and fans of rock music are probably to exhibit themselves dressing in tight and black leather trousers as they head bang their way to appreciate loud music. 

Though could not be regarded as a leather pants, leather chaps are typically affiliated with the Wild West or the cowboy customs. 

Several of the popular perception for those who put on these pants are something about being distinct or above the crowd (sense of rebellion) and self-expression (calling for freedom).