It was a pleasure to read Philip Enterline's [1991] extensive exploration of the literature on the likely relationship between asbestos exposure and lung cancer. I have no better explanations than his, as to why it took Americans 20 years longer to accept a relationship that the Germans had officially accepted.
Several thoughts do come to mind, however. The first is a modification of a clichk: "Proof, like beauty, lies in the eye of the beholder." I remember a remark made to me in the 1970s by a Canadian scientist concerned for his country's asbestos industry: "Schneiderman, you must understand, asbestos is to Canada as tobacco is to the United States." There are still some scientists who do not accept the smokinglung cancer relationship. I do not know who suggested it first, but I recall a phrase that went something like "Proof will occur when the last of the opponents (to the idea) dies." And, finally, I suppose, one must consider the Herr Doktor Professor syndrome common in countries where authority is taken very seriously. In such a society, if HDP says it, it must be true. If you are an academic and think it not true, and say so publicly, one would believe you had a source of income other than your academic appointment. On the other hand, the bumper sticker advice "Challenge Authority," may stand Americans in good stead. Notice that, in both of Professor Enterline's tables, a major late (1964) disbeliever was the American College of Chest Physicians.
By requiring stiff hurdles to the acceptance of proof, U.S. science may have outrun intuition (I refrain from making a value judgment on whether this is good or bad). Several years ago, Marvin Zelen conducted an experiment in intuition vs. statistical significance as a basis for judgment. I had constructed, with the help of Peter Armitage, several closed sequential schemes. Zelen had available to him the returns as they came in from a painvise controlled clinical trial. To a substantial audience (of nearly 100 people, as I recall), we presented each sequential painvise result (i.e., A > B or B > A), with the instruction that the participant record when