From Wired's blog : The Japanese are more accepting of robots because they don't suffer from the Judeo-Christian guilt or fear associated with making idols, according to Jean-Claude Heudin, a researcher at the University of Paris.
He explained to Wired.co.uk that because of Exodus 20 ("You shall not make for yourself an image in the form of anything in heaven above or on the earth beneath or in the waters below", i.e. no idols) many Westerners see the creation of life or something as lifelike as a robot as a transgression of some sort of moral law. For that reason we have scary iconic figures such as Dr Frankenstein's monster and Golem (of Jewish folklore, not LOTR, fame) and frequent Hollywood robot horror movies such as Terminator to pollute our attitudes towards robots.
Heudin says: "That explains a bit culturally why the first impression about this technology is one of anguish, unlike our Japanese contemporaries where robots are viewed as a companion of life or the saviour of humanity."
Fujiko Suda, the Japanese founder of Project Kobo, agreed with Heudin, talking of a culture of Japanese accepting robots as friends. When asked why a lot of robotic innovation was coming from Japan and Korea rather than Europe and the US, she responded: "I think it's that religious difference. In Japan we don't have this one god who created mankind. When you create robot it can feel too godlike. We have eight million gods. God is in everything. So if you have a human-shaped robot, it's just another thing in nature that we work with. We're not afraid of it. "
It is certainly true that Japan has the world's highest use of industrial robots and that it specialises in humanoid types. However, there are no major studies that support this hypothesis. So while it's certainly an interesting theory, it will have to remain as such until it is scrutinised more scientifically.