A Critical Review of Selye’s Stress Theory: The Statistical Analyses of Selye’s Own Experimental Data Disprove It

Abstract

Selye’s article (Selye, 1936a) published in “Nature” has been enormously cited and markedly affected the entire field of “stress”, until today. The key concept of Selye’s stress theory was “the principle of nonspecificity”. Selye defined stress as the nonspecific responses of the body to various noxious agents. He gave various noxious stimuli to rats, and reported the results in his paper (Selye, 1936b). However, he described only raw data (thymus, and adrenal weights in individual rats), without even the mean values. This study analyzed those data statistically. Among his data, the result pattern most frequently observed was the both occurrences of thymus involution and adrenal enlargement. It appeared to give a conclusive evidence for Selye’s theory. However, there were also other two result patterns. The second pattern was a significant decrease in the thymus weight without changes in the adrenal weight (fasting for 24 - 96 hours in 3-month-old rats, morphine injections, and skin lesions). The third pattern was no change in either the thymus or adrenal weight (exposure to heat and bone fractures). These results disproved Selye’s theory of nonspecificity and they forsook it. And moreover, it was suggested that Selye’s results themselves supported Mason’s proposal that all stress responses were elicited through psychological emotional reactions (Mason, 1971), which were very compatible with the recent psychological stress theories.