This is only interesting if one doesn't realize that sign language is its own language, rather than simply signed English. Syntax and word order are entirely different, and much information is encoded in what one might call 'tone'—eg, the energy or rhythm with which any sign is performed—that in English would be communicated with full words or suffixes.
These facts are patent to anybody with a passing acquaintance of American (or any other sign language). The 'paradox' they're discussing here is tantamount to saying, 'Japanese words tend to be longer than English words. So how do the Japanese communicate as effectively as we do?'
These facts are patent to anybody with a passing acquaintance of American (or any other sign language). The 'paradox' they're discussing here is tantamount to saying, 'Japanese words tend to be longer than English words. So how do the Japanese communicate as effectively as we do?'