Extraversion: sociability and impulsivity?

The sociability and impulsivity components of extraversion were studied. Thirty experimental items were written to assess different aspects of sociability and impuslivity. These items, along with the 24 extraversion items of the MPI, were administered to 146 college students. Factor analyses of experimental items indicated that neither sociability nor impulsivity is unitary. Correlations among these sociability and impulsivity factors and the MPI extraversion items indicated that MPI extraversion is essentially a measure of one aspect of sociability: the quantity of social relationships. Extraversion touches on but does not adequately sample either the intensity (quality) of social relationships or aspects of impulsivity.