We start from an approximately 8 billion person baseline. Each trait has an estimated prevalence. The model starts with your rarest selected trait, then applies prototype overlap weights of 14% within a domain and 28% across domains. Those weights are explicit modeling assumptions, not measured joint correlations.

Country and regional shares are rounded from UN World Population Prospects 2024 estimates; the country list includes all 193 UN members plus Palestine and the Holy See. For major languages, Ethnologue total-speaker counts (native and second-language users) are scaled against 8 billion. Handedness uses a global meta-analysis. Eye color, hair color, sibling counts, identity, personality, and everyday preference rates are broad estimates because representative global data is limited and rates vary by place and generation.