The predictability of Type A behaviour was measured in a sample of 375 professionals with
a shortened version of the Jenkins Activity Survey (JAS). Two structural equation models were
constructed with the Type A behaviour achievement sub-scale and global (total) Type A as the
predictor variables. The indices showed a reasonable-to-promising fit with the data. Type A
achievement was reasonably predicted by service-career orientation, internal locus of control,
power self-concept and economic innovation. Type A global was also predicted by internal locus of
control, power self-concept and the entrepreneurial attitude of achievement and personal control.