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People leave more behind them than a name. Like her fictional protagonist Victor Frankenstein, Mary Shelley is survived by her creation: Frankenstein took on a life of his own within our collective imagination (Figure S15). Such legacies, and all the many other ways in which people achieve cultural immortality, fall beyond the scope of this initial examination.

III.8. History of Technology

A list of inventions from 1800-1960 was taken from Wikipedia (Ref S10).

The year listed is used in our analysis. Where multiple listings of a particular invention appear, the year retained in the list is the one reported in the main Wikipedia article for the invention. (e.g. "Microwave Oven" is listed in 1945 and 1946; the main article lists 1945 as the year of invention, and this is the year we use in our analyses).

Each entry's main Wikipedia page was checked for alternate terms for the invention. Where alternate names were listed in the main article (e.g. thiamine or thiamin or vitamin B1), all the terms were compared for their presence in the database. Where there was no single dominant term (e.g. MSG or monosodium glutamate) the invention was eliminated from the list. If a name other than the originally listed one appears to be dominant, the dominant name was used in the analysis (e.g. electroencephalograph and EEG - EEG is used).

Inventions were grouped into 40-year intervals (1800-1840, 1840-1880, 1880-1920, and 1920-1960), and the median percentages of peak frequency was calculated for each bin for each year following invention: these were plotted in Fig 4B, together with examples of individual inventions in inset.

Our study of the history of technology suffers from a possible sampling bias: it is possible that some older inventions, which peaked shortly after their invention, are by now forgotten and not listed in the Wikipedia article at all. This sampling bias would be more extreme for the earlier cohorts, and would therefore tend to exaggerate the lag between invention date and cultural impact in the older invention cohorts. We have verified that our inventions are past their peaks, in all three cohorts (Fig S16). Future analyses would benefit from the use of historical invention lists to control for this effect.

Another possible bias is that observing inventions later after they were invented leaves more room for the fame of these inventions to rise. To ensure that the effect we observe is not biased in this way, we reproduce the analysis done in the paper using constant time intervals: a hundred years from time of invention. Because we have a narrower timespan, we consider only technologies invented in the 19th century; and we group them in only two cohorts. The effect is consistent with that observed in the main text (Fig S16).

III.9. Censorship

III.9A. Comparing the influence of censorship and propaganda on various groups

To create panel E of Fig 6, we analyzed a series of cohorts; for each cohort, we display the mean of the normalized probability mass functions of the cohort, as described in section 1B. We multiplied the result by 100 in order to represent the probability mass functions more intuitively, as a percentage of lifetime

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