Kitayama surveyed American and Japanese participants, and in the Americans he found a correlation between feeling so-called negative emotions (for example, sadness) and increased inflammation. But--and here's the fascinating bit-- there was no such correlation with the Japanese.
Kitayama's conclusion was that Americans believe 'negative' emotions are harmful, and so they are!
Americans are so sure that 'negative' emotions are bad for them, that they feel anxious about feeling them--in other words, Americans feel bad about feeling bad, and their body's reaction reflects that extra layer of stress. Americans feel threatened by such feelings, whereas Japanese do not.
Kitayama concludes that for Americans, feeling bad is more stressful than it is for Japanese, because it is felt as a “source of threat to self-image”, whereas in Japanese culture, it is understood to be “natural and integral to life”.
You can read more about it here.
