Among other reasons, it can be a way to signal trust.
When I became a mother five years ago I naively assumed that having a child meant a woman had grown up. Gone would be the petty insecurities, comparisons and judgements that women so cruelly share during the teenage years and beyond. I was wrong.
Spreading gossip works two ways. We've all heard someone claim "I don't gossip, I can't stand it," and then watch them happily take in whatever piece of news someone is sharing. Just because you're not the one spreading word, that doesn't make you guiltless.