abilities, personality traits, psychopathology) are at least moderately
heritable, that is, genetic in origin (usually 40–70 percent). Heri-
tability,orh^2 ,is the ratio of genotypictophenotypicvariation in a trait
in the population studied. Stated another way, it is the proportion
of variation in an observed trait such as IQ (the denominator) that
can be traced to genetic variation in the population (the numera-
tor). Heritability is a characteristic of groups in specific times and
places and does notreflect the proportion of an individual’sIQ score,
for instance, that is genetic in origin.
2.Heritability of more culturally specific attitudes and behaviors.
Individual differences in more culturally channeled attitudes, beliefs,
and behaviors (including religious beliefs, political preferences,
social attitudes, vocational interests, and self-perceived competence)
also tend to be somewhat heritable, with degree of heritability rang-
ing widely (0–60 percent). For instance, the heritabilities of tradi-
tionalism, sexual attitudes, and religious attitudes have been estimated
at 50 percent; attitudes about taxes, the military, and politics are
lower (15–30 percent; Plomin et al., 2001, p. 246). Individual dif-
ferences in vocational interests are about 40 percent heritable
(Betsworth et al., 1994), and differences in self-rated competence are
even more heritable (50–60 percent for self-rated physical appear-
ance and social, athletic, and scholastic competence; McGuire et al.,
1994). People obviously do not have genes for attitudes on taxes or
the military, but being more conservative than other citizens on such
matters may stem, for example, from more basic differences in per-
sonality, such as traditionalism.
3.Heritability of life outcomes. It may seem surprising at first, but
individual differences in life events and adult outcomes also tend to
be moderately heritable. Examples are level of education (60–70 per-
cent), occupation (50 percent), and income (40–50 percent). More
controllable events (for instance, conflicts with children or a change
in financial status) tend to be more heritable than less controllable
ones (death or major illness of child or spouse; estimates are 40 per-
cent for controllable events versus 20 percent for less controllable
ones; Plomin, Lichtenstein, Pedersen, McClearn, & Nesselroade,
GOTTFREDSON’S THEORY OF CIRCUMSCRIPTION, COMPROMISE, AND SELF-CREATION 111