Cattiness is something most women will have to deal with in the course of their lives. The modern word for catty is passive-aggressive and this particular form of nastiness is much more typical for females though there are enough men nowadays who also exhibit passive-aggressive traits.
There are two chief ways to be catty, it's either making disparaging and discouraging remarks about things other people hold dear or asking malicious questions, especially about things other people prefer not to talk about. Of course, some folks are just inquisitive by nature and don't necessarily mean harm, but most of us can distinguish pretty well between friendliness and even curiosity vs maliciousness.
Cattiness is often driven by jealousy and the feelings of inferiority. The good example of a catty person in literature is Lucy Steele from Sense And Sensibility. She makes a great show of befriending Elinor but her only objective is to to gloat over the misfortunes of the latter and try to profit from their friendship by all means possible. Elinor, being a much superior individual, never answers her in kind.
Lucy Steele is hardly portrayed as a role model yet by some strange reason many women delight in denigrating each other and being as mean to other females as possible. Sometimes I just wonder why so many ladies who often have good husbands and healthy children appear to be so dissatisfied with their life that they feel the need to constantly attack and demean those of their sisters who demonstrate a modicum of satisfaction with their circumstances. It's like some other woman being content is an insult to them.
Our society in general thrives on negativity. MSM are constantly trying to either shock or guilt trip us, there is constantly a crisis going on apparently; and if things are OK in your own country at the moment you are supposed to worry about the looming WWIII, a civil war in some third world country, global warming (caused by evil Westerners) and stuff like that. It went so far I seldom watch the news any more.
The Bible teaches us to rejoice with those rejoicing not go around spreading doom and gloom and being overall wet blankets and please don't forget that looking at the bright side is a choice!