Definition of "extraversion"

...the supposed Extraversion or Intraversion of Sulphur...

1675, Robert Boyle, “Of the Imperfection of the Chymist's Doctrine of Qualities”, in The Mechanical Origine or Production of Corrosiveness and Corrosibility, page 36

I called the hysterical type the extraversion type and the psychasthénic type the introversion type.

1915, Carl Jung, “On Psychological Understanding”, in Journal of Abnormal Psychology, number 9, page 396