You’re definitely right that those studies have a pretty limited scope in terms of what sorts of interactions they would inform. Clearly, millions of healthy marriages and friendships between people of different skin colors demonstrate that the ‘empathy gap’ (as it’s being called) is probably negligible when it comes to forming a real relationship.
But the place where those studies could have some real bearing are in those interactions you mention where there isn’t a real relationship between people. The criminal justice system is a good example, where you have a series of short term interactions (with police, jurors, judges), all of which can lead to a person receiving different treatment because of marginal differences in empathy at each stage. Measuring the actual effect is obviously very difficult, but it seems irresponsible not to give some credence to a phenomenon that has been scientifically observed and could have a real impact on people’s lives (like time spent in prison or not).
As for what Emma was implying with her statement, of course she is the only one who really knows what she was thinking, and I am making a little bit of a jump in assuming she’s talking about those studies. But the ‘empathy gap’ idea is actually pretty widely cited in left-leaning blogs these days, so I think I’m making a pretty safe bet with my interpretation. For the record though, I would be right there with you, and would not defend her, if I thought she was actually doing as you suggest, and just projecting her own lack of empathy on all white people.