Bool vs boolean - What's the difference?

Bool vs Boolean

Without getting in contact with people who were actually involved in these design decisions, I think we're unlikely to find a definitive answer. However, based on the timelines of the development of both Java and C++, I would conjecture that Java's boolean was chosen before, or contemporaneously with, the introduction of bool to C++, and certainly before bool was in wide use. It is possible that boolean was chosen due to its longer history of use (as in Boolean Algebra), or to match other languages (such as Pascal) which already had a boolean type.

Historical context According to Evolving a language in and for the real world: C++ 1991-2006, the bool type was introduced to C++ in 1993. Java included boolean in its first release in 1995 (Java Language Specification 1.0). The earliest language specification I can find is the Oak 0.2 specification (Oak was later renamed to Java). That Oak specification is marked "Copyright 1994", but the project itself was started in 1991, and apparently had a working demo by the summer of 1992.