That's a mutant version of its history.
lets see what wikipedia says about this mutant version of history:
On the wikipedia page for Scheme, under the origin section it says:
/wiki/Scheme_%28programming_language%29#Origin
Scheme started as an attempt to understand Carl Hewitt's Actor model, for which purpose Steele and Sussman wrote a "tiny Lisp interpreter" using Maclisp and then "added mechanisms for creating actors and sending messages."
"Actor model" is highlighted blue in the proceding sentence which means its a link to another wikipedia page, when I click it then I read:
http://en.wikipedia.org/wiki/Actor_model
In computer science, the Actor model is a mathematical model of concurrent computation that treats "actors" as the universal primitives of concurrent digital computation: in response to a message that it receives, an actor can make local decisions, create more actors, send more messages, and determine how to respond to the next message received.
further down on the Actor Model wikipedia page it mentions something about Smalltalk:
http://en.wikipedia.org/wiki/Actor_model#Smalltalk
Alan Kay was influenced by message passing in the pattern-directed invocation of Planner in developing Smalltalk-71. Hewitt was intrigued by Smalltalk-71 but was put off by the complexity of communication that included invocations with many fields including global, sender, receiver, reply-style, status, reply, operator selector, etc.