In The Washington Post (free registration required), I found this article, Human Responses to Technology Scrutinized. The article shows that people tend to anthropomorphize their computers, often seeing them and treating them as they would actual people. Which brings us to this disturbing anecdote:

A German carmaker recalled an automobile with a computerized female voice issuing navigation information -- because many men refused to take directions from "a woman."

Interesting that a super-compressed identity signifier such as a gendered voice can trigger such a strong response.