Intelligence quotient tests | Blaming mothers | ‘Wafer-thin mint’ dangers | Kemi Badenoch | Leadership shelf life | Sudoku rules

I’m no academic, but I think I am intelligent enough to understand that IQ is a very unreliable means of assessing intelligence, never mind when it is in the hands of a biased researcher (Publisher reviews national IQ research by British ‘race scientist’ Richard Lynn, 10 December).
Joan Lewis
Saint-Étienne-de-Gourgas, France

• Of four letters (10 December) on Mary Ann Sieghart’s piece prompted by the Gregg Wallace thing (Why do some men behave badly? I think I have the answer, 6 December), two say it’s women – specifically mothers or female bosses – who are to blame. Sheesh.
Julia Crouch
Brighton