 22. The Approach System as a Component of Personality 491
to higher scores on both BAS and BIS mea -
sures. However, these associations between 
BIS and BAS are never very strong. If a gen -
eral reactivity is responsible for it, that over -
all reactivity clearly does not overwhelm the 
separate sensitivities.
Some researchers have proposed that a 
strong reactivity to nonreward would be ex -
pected if a person has a strong motivation 
to achieve rewards (e.g., Carver, 2004; Corr, 
2001). To address this possibility directly, 
Wright, Lam, and Brown (2009) developed 
a five-item Frustrative Nonreward subscale 
to append to the BIS/BAS. This scale cor -
relates with both the BIS scale and Reward 
Responsiveness, but not the other two BAS 
subscales. This finding is consistent with the 
idea that those who are most responsive to 
reward also experience stronger negative 
emotions when reward-  related goals are 
thwarted, but the negative emotions appear 
specific to emotional responses to reward 
and its absence.
Age and  Gender Differences 
in Approach  Motivation
Several studies have reported gender dif -
ferences in responses on these self-  report 
scales. Women scored higher than men on 
Reward Responsiveness (Carver & White, 
1994; Jorm et al., 1999), and in one study, 
scored lower on Drive (Jorm et al., 1999). 
In contrast, men reported greater sensitivity 
to reward, on average, than women on the 
SPSRQ, perhaps reflecting the greater focus 
on impulsivity of the SR subscale (Torrubia 
et al., 2001).
Considerable evidence suggests important 
changes in reward sensitivity across the lifes -
pan, with a peak of reward sensitivity dur -
ing adolescence (Somerville, Jones, & Casey, 
2010). Cross-  sectional findings indicate that 
adolescents, as compared with children and 
adults, have stronger responsivity to re -
wards, including monetary incentives (Har -
din, Schroth, Pine, & Ernst, 2007; Jazbec et 
al., 2006) and positive feedback (Cauffman 
et al., 2010), whether measured by posi -
tive affective displays (Ernst et al., 2005) or 
neural responsivity (Van Leijenhorst et al., 
2010). In a longitudinal study, Uroševi ć, 
Collins, Muetzel, Lin, and Luciana (2012) 
found an increase in reward sensitivity coin -ciding with early to late adolescence, with a 
stabilization in the early 20s corresponding 
with decreases in volume in the left NAcc. 
At the other end of the age spectrum, in -
vestigators have found lower BAS scores 
in older adults, suggesting that BAS may 
weaken over time (Jorm et al., 1999); this 
is consistent with reports that dopaminergic 
function decreases later in life (S. Li, Linden -
berger, & Backman, 2010).
Beyond these normative developmental 
patterns, reward sensitivity has shown sta -
bility over time. Studies using the BAS scale 
have shown exceptional test–  retest reliabil -
ity over two years (Brown, 2007; Carver & 
White, 1994).
There is some question about whether 
these scales adequately capture BIS/BAS 
levels in children. In a sample of 284 chil -
dren ages 8–12 years, factor analysis did not 
support the four-  factor structure described 
earlier (Muris, Meesters, de Kanter, & Tim -
merman, 2005). Rather, BIS and BAS items 
appeared to form two orthogonal dimen -
sions, each with satisfactory internal consis -
tency (.81). There was also an unexpectedly 
strong relationship between BIS and overall 
BAS, suggesting that items may not general -
ize well to this younger group.
A more recent project examined samples 
of children, adolescents, young adults, and 
later adults (approximately age 36) and de -
termined that Fun Seeking did not differen -
tiate well from the other BAS factors and a 
few other items had suboptimal psychomet -
ric properties across the age groups (Pagliac -
cio et al., 2016). Use of a trimmed model 
that omitted Fun Seeking and the subopti -
mal items yielded evidence of consistent fac -
tors across age groups. Consistent with ear -
lier results, BAS scores tended to be highest 
in young adulthood and lower in childhood 
and later adulthood, exhibiting a nonlinear 
relationship across development.
Biological and  Behavioral Correlates 
of Self‑Report  Measures
The self-  report scales discussed here have 
all been linked to behavioral, physiological, 
and neural responses to appetitive stimuli. 
With respect to overt behavior, research 
has linked TEPS Anticipatory Pleasure and 
BAS scores with willingness to exert greater 