Definition:

Concrete thinking is literal thinking that is focused on the physical world. It is the opposite of abstract thinking. People engaged in concrete thinking are focused on facts in the here and now, physical objects, and literal definitions. The term “concrete thinking” is, ironically, a metaphor (and a metaphor is a type of abstract thinking); concrete is a hard, physical substance and concrete thinking is focused on literal–and often physical–facts. A person who thinks only in concrete terms might think that the term “concrete thinking” means thinking literally about concrete.

Further Reading:

Book: Agile Competitors and Virtual Organization by Steven L. Goldman, Roger N. Nagel and Kenneth Preiss