As early as the nineteenth century in Europe, case reports of children ... influence IQ scores, such as quality of instruction, enriching classes and afterschool activities, entering school ...

Focusing first on the children taking the drama class, Schellenberg found they "didn't differ [in increased IQ] from those in ... suggest that extracurricular activities are indeed enriching ...

Extracurricular activities such as chess lessons or science programs, in which none of the 132 students was involved, may also nudge IQ upward, Schellenberg theorizes. The children’s scores on a ...