[YouTube] First Course on Fragility, Convexity, and Antifragility (Nontechnical)

A first, very introductory presentation of fragility as linked to both nonlinearity and dislike of variations. Antifragility is almost the opposite, limited to a specific range of variations.


  • Why everything fragile must be concave.
  • The medical S curve.
  • Why harm to the climate is necessarily nonlinear in dose response.
  • How hospitals can be overcrowded unless there are redundancies.

Further discussions will be more technical.

[YouTube] Correlation measures are misused in the presence of nonlinearities

Correlation measures are misused in the presence of nonlinearities.

(How a measure of unintelligence can give the illusion of high correlation with performance.)

Correlation measures are not supposed to be used in the presence of nonlinearities. When 2 variables correlate half the time (in a symmetric way around the mean), correlation will not be 50% but will show ~90%. Part of debunking IQ studies. If IQ works for disabilities but does not correlate with success, there is an illusion of correlation because of the biases in the metric.