The late John Gumperz, a linguist known for his research on differences in the ways cultures communicate, was called to Heathrow International Airport in the mid-1970s to try to figure out why the new employee cafeteria workers (women from India and Pakistan) and a group of baggage handlers had become very hostile to each other. The women were accused of being rude and they said the baggage handlers were discriminating against them.
When the linguist recorded their conversations, he found that the main "culprit" was how the cafeteria workers were asking the baggage handlers if they wanted "gravy." They were not using an upward questioning tone, "Gravy?" that would sound like the polite question, "Would you like gravy?" They were using a falling intonation, "Gravy!" which sounded like, "This is gravy so take it or leave it." To the baggage handlers, these women sounded really rude.
But Gumperz knew (and I have discovered by listening to my clients from India and asking them), that the reverse is true for speakers of Indian languages including Tamil, Telugu and many others. So if, while being tested, my client responds with, "I am a software engineer? I have two children?" I know that he thinks he is making a statement. However, if he gives a report at a team meeting and his colleagues hear him say, "Our project is going well?" or "This is my solution?" he will sound like he isn't really sure that what he is saying is true!! This creates a really bad impression of his competence. No one is wrong, but in an American (or British) work environment, awareness of the negative impact of "uptalk" is critical.
The article goes on to discuss similar cultural misunderstandings that can occur during job interviews. The title to this section is a link to the NPR article.