Since people who live together tend to share a common diet and habits of energy expenditure it is reasonable to expect similarities in serum and urinary vitamin levels, in hemoglobins and hematocrits, blood lipids, fatness levels and—over time—in selected outer dimensions. This expectation is confirmed by dietary, biochemical and anthropometric comparisons of genetically-unrelated individuals who live together, i.e. parents and children, siblings, spouses, adoptive parent- child pairs and unrelated “siblings. ” Such similarities are notable for vitamins A and C, serum cholesterol, outer fatness and for long-term fatness changes (A fat) of both genetically-related and genetically-unrelated family members. Even stature suggests a long-term effect of living together. Collecting these similarities as examples of the cohabitational effect, it is suggested that many family-line resemblances are inflated by the results of living together, and that resemblances between contiguous populations may also reflect similarities in energy intake, energy expenditure, diet and nutrition.
Garn, Stanley M.; Cole, Patricia E.; and Bailey, Stephen M.
"Living Together as a Factor in Family-line Resemblances,"
4, Article 11.
Available at: https://digitalcommons.wayne.edu/humbiol/vol51/iss4/11