A Programmed Approach

Historically, classroom learning used to be about mastering the subject content, preparing children for a society that had dedicated professions awaiting them. Mastery of subject matter ensured success in a profession. 

Explicit and targeted teaching of intelligence by isolating children's thinking skills from the subject content, was not a big part of mainstream education system historically. 

THINKING WAS ALWAYS IMPLICIT IN THE CONTENT BUT HARDLY MADE VISIBLE.

In the past, therefore, when children showed signs of struggle in their ability to learn they were most likely placed in remedial lessons which provided a more intensive focus on the prescribed content and subject matter, albeit in modified version for the slow learner. 

Rarely was the child's basic ability to effectively apply their inner thinking functions addressed in a systematic fashion, isolated from their subject content. 

Rarely was the question asked "Has this child got mastery over their own thinking processes regardless of which subject he or she is learning?". 

Rarely, if ever, was thinking skills taught explicitly in traditional classrooms.

Modern classrooms, however, place more emphasis on a child's brain functions and how they apply their thinking skills. The idea of "igniting their dormant thinking functions, is more broadly accepted now within the mainstream education system. 

School curriculum places very heavy emphasis on a child's ability to think critically and creatively. Children achieve much higher marks when they apply effective thinking and higher order thinking skills in their academic assignments.

All subjects regularly make thinking skills visible so children can understand it better.