Thanks for the link and the tip Jessica, much appreciated.
For those readers curious as to the detailed answer to this question here is a post, over two years old, which quite a definitive response:
Check out this quote from the Java Virtual Machine Specification:
Although the Java virtual machine defines a boolean type, it only provides very limited support for it. There are no Java virtual machine instructions solely dedicated to operations on boolean values. Instead, expressions in the Java programming language that operate on boolean values are compiled to use values of the Java virtual machine int data type.
The Java virtual machine does directly support boolean arrays. Its newarray instruction enables creation of boolean arrays. Arrays of type boolean are accessed and modified using the byte array instructions baload and bastore.2
The Java virtual machine encodes boolean array components using 1 to represent true and 0 to represent false. Where Java programming language boolean values are mapped by compilers to values of Java virtual machine type int, the compilers must use the same encoding.
This is consistent with the fact that byte, short and char are almost always promoted to int the moment they are used in any calculations. Java is set up to assume that a four-byte int is the smallest natural word length on any machine it's running on, so in many cases there's little point in trying to use a smaller value.
And check out this footnote:
In Sun's JDK releases 1.0 and 1.1, and the Java 2 SDK, Standard Edition, v1.2, boolean arrays in the Java programming language are encoded as Java virtual machine byte arrays, using 8 bits per boolean element.
And, from the API for writeBoolean() in DataOutputStream:
Writes a boolean to the underlying output stream as a 1-byte value. The value true is written out as the value (byte)1; the value false is written out as the value (byte)0.
(Quotes :Jim Yingst, May 15, 2000)