It degrades the consciousness. This is what the Mother herself has said about it.
‘Every word spoken uselessly is a dangerous act of gossip.
What then can we say of malicious gossip, of slanderous speech? One who indulges in this form of incontinence debases his consciousness.
And when to this incontinence is added the habit of vulgar quarrelling expressed in crude terms, then it is equivalent to suicide, the suicide of the spiritual life in oneself.’
So you see gossip is indeed quite a dangerous thing.
Affectionately,
Alok Da