Cancer and Smoking

Abstract

IN a letter published in Nature of August 30, p. 596, Sir Ronald Fisher quoted figures confirming previous observations that smoking habits are more similar in identical than in fraternal pairs of twins even when the identical pairs are reared apart. The result can be interpreted as showing that, like almost every trait, mental or physical, previously tested by the twin method, smoking habits are, to a greater or lesser degree, dependent upon genetical constitution. It is, however, difficult to appreciate the ralevance of this demonstration to the problem as to whether or not cigarette smoking causes lung cancer.