An important hypothesis in the study of media-defined as the means of mass communication-is that media affect our historical records by biasing the types of content that we can transmit (e.g. film or audio recordings) and the amount of content we can record. Here we test this hypothesis by looking at data on historical characters, and their occupations, as a proxy for the amount and type of information we now remember from each historical period. We find that changes in communication technologies, including the introduction of printing and the maturity of shorter forms of printed media-such as newspapers, journals, and pamphlets-were accompanied by sharp increases in the number of memorable biographies from a time period that are present in current online and offline sources. Moreover, we find that changes in media technology, such as the introduction of printing, film, radio, and television, coincide with sharp shifts in the occupations associated with the individuals present in both of these biographical records. These findings suggest that communication technologies shape our species historical records by constraining the amount and types of information we can record.In a separate paper, they explain this more clearly.
The second question was whether the number of famous people has increased simply because the population of the world has increased. Our data shows that this is not the case. For centuries, the growth in famous people has been outpacing that of global population. As you can see in this paper and in this short talk, the number of famous people born in a given year used to be a fraction of global population prior to the invention of printing, and also, for the 200 years after printing (although it was a larger fraction). Since the late seventeenth century, however, the number of famous people born in each year has been proportional to the square of global population. That is, the number of births of famous people, divided by the population of the world at that time, has been increasing linearly over time. Moreover, that proportionality constant has increased with the introduction of new communication technologies. The slope that emerged with the popularization of shorter forms of printing, like journals and newspapers in the late seventeenth century, increased with the introduction of new communication technologies, like film, radio, and television. So in the twentieth century we produced famous people at a rate we never did before.