Definition of "ascender"

Catherine had a paperback called Graphology: The Mind in the Hand, which gave her all sorts of warnings about people’s tendencies and repressions (“Artist or Madman?” “Pet or Brute?”). “It's those enormous ascenders, darling,” she said: “I see a lot of ego.”

2004, Alan Hollinghurst, chapter 1, in The Line of Beauty […], 1st US edition, New York, N.Y.: Bloomsbury Publishing