It seems only common sense that happiness should be good for our physical health, but psychological research has sent mixed signals in recent years. Some studies have found it is, while others have found no effect, and some even a negative effect.

In a new article published in the Journal of Happiness Studies, Professor Ruut Veenhoven of Erasmus University offers a possible solution to this question. In reviewing 30 studies, he finds that the neutral and negative findings for the effects of happiness on health are in studies on people who were ill at the time.

In comparison, studies on people who were in good health do find a strong positive effect for happiness on health. Professor Veenhoven suggests that happiness may not have a beneficial effect on the physical health of those who are ill, but it does help prevent people falling ill in the first place.

A particularly spectacular study on nuns found that those who were happiest in early life lived 10 years longer than those who were unhappy. Another study of 660 inhabitants of Ohio found that higher levels of happiness translated, on average, into 7.5 years more life.

人們似乎普遍認為幸福有利于我們的身體健康，但心理學研究在近些年得出一個復雜的訊息。一些研究發現幸福確實有助于我們的身體健康，而其他研究卻發現幸福對我們的身體健康毫無任何影響，甚至有些研究表明幸福對我們的身體健康有著消極影響。

荷蘭鹿特丹大學教授魯特‧維恩霍文在《幸福研究雜志》上發表的一篇最新文章中，為我們找到了這一問題的答案。在回顧自己30年以來的研究時，他發現，幸福對健康所具有的不確定和消極影響只是對那些處在患病時段的人的研究。

相比之下，在對那些身體健康的人的研究過程中，發現幸福對健康確實存在巨大的積極影響。維恩霍文教授提出，幸福可能對那些患病人群的身體健康沒有有利的影響，但它可以首先幫助人們避免生病。

一項特別對尼姑的驚人研究發現，那些在早期生活得最幸福的尼姑通常比那些不幸福的尼姑長壽10年。另一項對660名俄亥俄州居民的研究發現，那些幸福感越高的人往往平均壽命會增加7.5年。