As I understand it, this means that tieflings somehow "feel" celestial heritage, which triggers negative reaction.Aasimars, bariaurs, and wildren often trigger instinctive fear or revulsion in tieflings, making it difficult for them to work together at all.
I.e. if tiefling A meets non-obvious aasimar B, then A is very likely to feel dislike towards B, even without knowing B's race.
Is this correct?