> In a mathematical model of collective intelligence I think we need to also include a "productive use" factor. The total brain power of our species might be higher than in the past based on a summation, but how much per-capita intelligence is being utilized for productive/adaptive ends versus being being distracted from such ends? What's our distraction rate offset?

Excellent question. Global GDP estimates going back to 1 CE are here [1][2]. I would argue that GDP is a good proxy for an estimate of the summation of per-capita intelligence being used for "productive" ends, by definition.

But, the global average GDP per capita is [3] with a similar hockey-stick curve, and it is unclear whether the per-capita intelligence used for "productive" ends has also been increasing similarly, because the confounding factor is the effect of tools as force-multipliers (impact on productivity). The Flynn Effect is the strongest indicator that yes, average intelligence has been rising as measured in certain populations where cultural differences do not wreck the applicability of IQ tests.

[1] https://ourworldindata.org/grapher/global-gdp-over-the-long-...

[2] https://web.archive.org/web/20260525015042/https://ourworldi...

[3] https://ourworldindata.org/grapher/global-average-gdp-per-ca...