Ok, provocative title out of the way. Referencing article here.
More provocative body text: if a lack of sarcasm indicates that a portion of the human mind is not working correctly, then the vast majority of native-born US citizens suffer from this affliction.
I have a hard time living in a society where a fine degree of sarcasm in not appreciated by so many people. I grew up in a culture where sarcasm and self-deprecation were the foundations of humour.
Maybe I am just missing the finer, more subtle, points of US culture.