What makes Johnson tick?

Sir, – Reading the headline on the excellent article by Bobby McDonagh, "We are still trying to figure out what makes Johnson tick" (Opinion & Analysis, July 31st), reminded me of the old joke about the well-spoken Trinity sociology student who, in conducting a survey, asked an old man on O'Connell Bridge, "What , in your opinion, makes a Dubliner tick?"

The reply: “I don’t know, he’s just tick.” – Yours, etc,

JOHN GLACKIN,

Howth, Co Dublin.