(Keller and Coventry 2005; Keller et al. 2010). Extended twin-family designs (which can make good estimates of these parameters) are only available for Neuroticism (closely related to Cloninger's Harm Avoidance), for which a very large (N=45,850) study including parents, aunts/uncles, and spouses estimated additive and nonadditive genetic influences in females at 34% and 13% respectively, and in males at 31% and 10%.
