"have turned into one of those awful McWhirterish ticks"

The brothers Norris and Ross McWhirter were the co-founders of the Guinness World Records. Known for their photographic memory, they frequently made appearances on the British television show Record Breakers, challenging audience members to test them on their detailed knowledge of the Guinness Book of Records. In 1951 they founded an agency to "supply facts and figures to newspapers, yearbooks, encyclopedias, and advertisers". 

Identical twins, here they make an American television appearance together in the 1960s: