Answer: CRYSTALIZED INTELLIGENCE
Explanation: basing on the fact that Ed's solutions to problems have become increasingly complex hints at the fact that he has developed what is known as crystalized intelligence.
Crystalized intelligence is defined as the accumulation of knowledge, facts, and skills that are acquired over a long period of time. This explains his ability to draw conclusions from experience-based information and knowledge when analysing issues.
Crystalized intelligence is in contrast with Fluid intelligence and are both the two factors of general intelligence first proposed by Cattell in 1971.