Personality resemblances between unwed mothers and their adopted-away offspring.

In a sample of 300 adoptive families there was a tendency for adopted children to be more extraverted and emotionally stable than biological children. For extraversion there was a low statistically significant resemblance between unwed mothers and their adopted-away children. Paradoxically, however, children of mothers with elevated Minnesota Multiphasic Personality Inventory (MMPI) scores tended to be rated as more emotionally stable than children of mothers with better adjustment on the MMPI. This latter finding was interpreted as suggested an interaction between emotional sensitivity and the early environment. According to this hypothesis, individuals with genotypes making them vulnerable to their environments could thrive in the warm climate of the adoptive families, but turn out relatively badly in the presumably less benign families in which the unwed mothers were reared.