ABSTRACT
Few generalizations have had as much support as the statement that things are usually more complicated than they at first seem. One common beginning step in scientific progress is the discovery of a “simple” relationship that spurs an army of researchers to investigate the factors involved in the relationship and their ramifications. The early phases of the important Framingham study of coronary heart disease now seem more limited in scope than they did 20 years ago because in the intervening years the roles of psychological and social factors in heart disease have become more widely recognized than they were at the beginning of that project. As a consequence, the complex of factors that must be considered in the study of heart disease has increased substantially. Even if, as sometimes happens, later results are contradictory, the subsequent inquiry often leads to the development of new methods and unanticipated discoveries and relationships.
