I would not guess this. I would guess instead that the majority of the population has a few “symptoms”. Probably we’re in a moderate dimensional space, e.g. 12, and there is a large cluster of people near one end of all 12 spectrums (no/few symptoms), and another, smaller cluster near the other end of all 12 spectrums (many/severe symptoms) but even though we see those two clusters it’s far more common to see “0% on 10, 20% on 1, 80% on 1″ than “0% on all”. See curse of dimensionality, probability concentrating in a shell around the individual dimension modes, etc.
I would not guess this. I would guess instead that the majority of the population has a few “symptoms”. Probably we’re in a moderate dimensional space, e.g. 12, and there is a large cluster of people near one end of all 12 spectrums (no/few symptoms), and another, smaller cluster near the other end of all 12 spectrums (many/severe symptoms) but even though we see those two clusters it’s far more common to see “0% on 10, 20% on 1, 80% on 1″ than “0% on all”. See curse of dimensionality, probability concentrating in a shell around the individual dimension modes, etc.