In the telepath caste, it was often the accident of possessing "laran", the specific telepath Gift, which determined how close a relationship would come. Caste, family, social position, all these became irrelevant compared to that one compelling fact; one had, or one did not, that inborn power, and in consequence one was stranger or kinfolk. By that criterion alone, the most important one on Darkover, Andrew Carr was one of them, and the fact that he was an Earthman was a small random fact without any real importance.