In reading the material on SPD I was able to isolate some sources in my own case: 1. my father had it (he died when I was 15), 2. parents not loving type, 3. growing up very isolated on a farm, and 4. I was an only child. I wonder if it helps to know this, it makes me feel more like a "normal" person than am abnormal one? So for me it is just going through life and avoiding people who will not like a person with SPD.