The attitude exhibited by Perth natives when they are out in public. Usually self-
superior and with the belief they are better than anybody who isn't from Perth and doesn't know their group of friends.
Similar to how a big fish
may act in a
small pond.
Guy 1:How'd you go with that
girl?
Guy 2:Terrible, she had a Perthonality.
Actions by a
girl from Perth (spoken with disdain)
Girl: Oh, so you're from the East Coast?... That's nice I guess...
(She then turns her back to you and starts another conversation with other Perthonalities)