Pure internalizing status, in comparison to control, co-occurring status, or especially pure externalizing status (see Footnote 2), was linked with impulsivity. In addition, when change in externalizing problems was taken into account, an increase in internalizing problems over time, in comparison to consistently low internalizing problems, was predicted by low impulsivity, although this association was infrequently found when co-occurrence of symptoms was not taken into account. Thus, very low impulsivity appears to be a harbinger of future internalizing problems for children who have not yet developed them, at least if they are not also high in externalizing problems. Such children likely are inhibited and inflexible in their control and may have difficulty developing adaptive ways to cope with novelty, stress, and negative emotion (see Davis & Nolen-Hoeksama, 2000). Such findings highlight the importance of spontaneity and the lack of overcontrol, likely because children very low in impulsivity (who tend to be behaviorally inhibited; Kagan & Fox, 2006) are less appealing to peers and less likely to approach and learn to cope with diverse situations. Blair and Diamond (2008) argued that
