Origin of the term "first-class object"

[Hung Jung Lu]

Hi,

Does anybody know where this term comes from?

"First-class object" means "something passable as an argument in a
function call", but I fail to see the connection with "object class"
or with "first-class airplane ticket". I just find the name a bit
strange. Also, if there are first-class objects, what would the
second-class objects or economy/tourist class objects be? :)

Just wondering,

Hung Jung