Emergenesis

In psychology, a trait (or phenotype) is called emergenic if it is the result of a specific combination of several interacting genes (rather than of a simple sum of several independent genes). Emergenic traits will not run in families, but identical twins will share them. Traits such as "leadership", "genius" or certain mental illnesses may be emergenic.

References

• Lykken DT, McGue M, Tellegen A, Bouchard TJ Jr. (1992) Emergenesis. Genetic traits that may not run in families. Am Psychol. 1992 Dec;47(12):1565-77. PMID 1476327