The scientific genius of THE REAL GHOSTBUSTERS, the EGON SPENGLER of DIMENSION 68-R, is the most drastically different from his prime dimension counterpart, and it's not just because he's a blonde.
This Dr. Spengler is more emotionally present, and is thus able to more easily connect with other people. (He's nowhere near as good at it as his colleagues, but he at least doesn't put strangers off!)
As gifted a theoretical engineer as he is a research scientist, Egon was primarily driven to his calling to paranormal research by a childhood encounter with a demonic presence known as THE BOOGIEMAN.