We are quite cognizant of the debate on the relative contributions of nature versus nurture towards the development of personality. We have become convinced that nature determines type, but nurture determines health within the type, and interestingly also determines variant (Social, Sexual, and Self-preservation). We have formed a theory on the environmental basis of variant, and are developing a testing instrument to test our hypothesis.
Our theory is that variant is determined in the first 18-24 months, and relates to the organization of the family unit and its health. Specifically we believe that social variant types were raised in households with multiple "care-givers" such as is seen in multigenerational home settings more common in the past, and split care families common these days where a child may be raised in multiple homes with multiple "Moms, and Dads" due to divorce and economic influences.
Sexual variant people, we believe, are products of either "Traditional" homes with Mom, Dad, and 1.5 kids, or in single parent households with strong generally healthy ties with the "primary care-giver".
Finally, self-preservation variant types are, we believe, those who for whatever reason, death, illness, disruption, or sibling displacement had a problem with their relationship with their "Primary care-giver(s)" during the critical (18-24 month) period of development of their variant.
We believe that variant is likely a cultural by-product. Pre-historic humans were generally organized into either nomadic or agrarian communities. In many nomadic cultures, each family unit predominantly fends for itself, so the children in those families would carry a survival advantage if they formed tight bonds with their mother. In agrarian communities the family unit was frequently multigenerational, so the children in those families carry a survival advantage if they can "hang" with the social group. In either of these settings if there was some disruption or dysfunction in the relationship of the child with its caregivers, then the child would have a survival advantage if it could fend for itself. We believe that variant is therefore determined in the first 18-24 months and depends on the child's home environment. This would explain why there is a preponderance of certain variants in different cultures around the world depending on the dominant family organization within that culture.