Why We GossipGossip evolved as a way of keeping track with what everyone in the tribe was doing. It began when humans gathered in large tribes, which consisted of more people that one person could talk to or keep track up from day to day. Essentially, gossip becomes a filtration process that helps people find out what's going on, without having to understand the boring, tedious, or superfluous stuff in between. It helps to pass information along large groups of people--information that might save lives.
Men don't spend as much time gossiping as women, seemingly naturally. This can be explained by a division of labor between males and females. Men were the hunters and traders who worked outside the village; females were left to domestic chores like cooking, cleaning, and tending to children because they weren't as physically strong or adept as the men. They spent more time socializing, and developed gossip as a way of staying safe. (For example--"He's a dangerous man, you should stay away" would be potentially lifesaving advice.)
Today, this tribe structure is still modeled by society as a whole, with celebrities and politicians being the powerful members of our "tribe". All these rags and airbrushed magazines are really just a way of catching snippets of information--true or not--about our 'leaders" as quickly as possible.
I think gossip among teenagers or women about one or more people in particular who are not popular or consequential may be a way of making themselves more powerful in their "tribe".