Table 4. Summary of Exploratory Factor Analyses.

Item	Problems
BIS1 ‘If I think something unpleasant is going to happen I usually get pretty worked up’	Weak loadings in early and late adolescents
BIS2 ‘I worry about making mistakes’	NONE
BIS3 ‘Criticism or scolding hurts me quite a bit’	NONE
BIS4 ‘I feel pretty worried or upset when I think or know somebody is angry at me	NONE
BIS5 ‘Even if something bad is about to happen to me, I rarely experience fear or nervousness	Weak loadings in children, formed separate factors with BIS7 in early and late adolescents
BIS6 ‘I feel worried when I think I have done poorly at something important’	NONE
BIS7 ‘I have very few fears compared to my friends’	Weak loadings in children, formed separate factors with BIS5 in early and late adolescents
RWD1 ‘When I get something I want, I feel excited and energized’	NONE
RWD2 ‘When I'm doing well at something I love to keep at it’	NONE
RWD3 ‘When good things happen to me, it affects me strongly’	Weak loadings in children and early adolescents
RWD4 ‘It would excite me to win a contest’	NONE
RWD5 ‘When I see an opportunity for something I like I get excited right away’	NONE
DRIVE1 ‘When I want something I usually go all-out to get it’	NONE
DRIVE2 ‘I go out of my way to get things I want’	NONE
DRIVE3 ‘If I see a chance to get something I want I move on it right away’	NONE
DRIVE4 ‘When I go after something I use a no holds barred approach’	NONE
FUN1 ‘I will often do things for no other reason than that they might be fun’	Weak loadings in adults, young adults, and children
FUN2 ‘I crave excitement and new sensations’	Weak loadings in late adolescents, cross-loadings in early adolescents and children
FUN3 ‘I'm always willing to try something new if I think it will be fun’	Weak loadings in late adolescents, cross-loadings in young adults, early adolescents, and children
FUN4 ‘I often act on the spur of the moment’	Loaded on own factor in young adults, late adolescents, and children

The wording of each item is presented in the left column; a description of the problems arising in the exploratory factor analyses is presented in the right column. This describes results of the EFA extracting all factors with eigenvalues greater than one. Problematic items cut in the revised model are in bold.