Theoretical estimates of the electron thermal diffusivity, driven by different instabilities to which tokamak plasmas are prone, are surveyed and their regions of validity specified. For those that are applicable, the prediction for a typical set of JET profiles is compared with the experimental local diffusivity. The predicted and experimental scalings of the thermal diffusivity with key parameters are also compared. Although no one model reproduces the magnitude, radial variation, and parameter scalings of the experimental thermal diffusivity, several models correctly predict some of the experimental behaviour.