So after he died, Albert Einstein's brain was preserved so it could be studied. Since his thoughts -- particularly regarding special and general relativity -- more or less changed the world and changed the way physicists looked at it, the intent was to see if any particular physical difference in his brain could explain some of his insight.
Although different studies had some initial results that showed some slight phsysiological differences between Einstein's brain and the average human brain, more detailed work suggests there are really very few such differences. In other words, genetics and whatever other factors one may believe play a role in creating a person didn't give ol' Albert any more to work with than they give anyone else.
It was all about what he did with it.