Remember those distant days when the Red Sox posed more of a menace to Yankee hegemony than the Orioles did? Turns out that dynamic -- in tandem with native hostilities toward those Sox -- infected certain Yankee fans with what can best be termed "geographical paranoia."
Their results, which also took into account participants' geographical expertise, supported the researchers' hypothesis: non-Yankees fans correctly estimated that Fenway Park was marginally farther than Camden Yards; in contrast, Yankees fans estimated that Fenway Park, the home stadium of a threatening group, was marginally closer than Camden Yards, the home stadium of a non-threatening group. Therefore, the relative difference in distance estimations to the two stadiums (Fenway Park and Camden Yards) differed as a function of the perceivers' baseball identity -- being a fan of the Yankees or not.
While science-y types would say that "social categorization, collective identification, and identity threat work in concert to shape our representations of the physical world," you are free to say that Yankee fans can't read maps.