extroversion

• extraversion

From extrovert +‎ -sion, a variant of extraversion popularized in psychology by Phyllis Blanchard's use of the variant (then nonstandard) spelling extrovert in her 1918 "Psycho-Analytic Study of August Comte".

extroversion (usually uncountable, plural extroversions)

1. The state or quality of being extroverted or an extrovert, particularly:
   1. (religion, obsolete) Consideration of the material world as an aid to spiritual insight.
      • 1656, Thomas Blount, Glossographia, s.v. "Extroversion":

        in mystical Divinity... a scattering or distracting ones thoughts upon exterior objects.

      • 1788, John Wesley, Works, volume VI, page 451:

        The turning of the eye of the mind from [Christ] to outward things [mystics] call Extroversion.

   2. (medicine) The condition of being inside out, especially in relation to the bladder.
      • 1835, Robert Bentley Todd, editor, The Cyclopaedia of Anatomy and Physiology, volume I, page 391:

        In extroversion of the bladder the anterior part of this organ is more or less completely wanting.

   3. (informal psychology) A personality orientation towards others and things outside oneself; behavior expressing such orientation.
      • 1920, Arthur George Tansley, The New Psychology and Its Relation to Life, page 88:

        Extroversion is the thrusting out of the mind on to life, the use of the mind in practical affairs, the pouring out of the libido on external objects.

      • 1999 October 29, Ben Brantley, “‘The Dead’: a Musical That Dares to be Quiet”, in New York Times:

        In a genre characterized by brassy extroversion, The Dead is a quiet revolutionary: a musical that dares to be diffident.

Technical papers in psychology overwhelmingly prefer the form extraversion used by Carl Jung, although the variant extroversion is more common in general use.

• (medicine): exstrophy
• (psychology): sociability

• (antonym(s) of “psychology”): introversion

• ambiversion
• extroversive
• extrovert, extroverted

• “extroversion, n.”, in OED Online ⁠, Oxford, Oxfordshire: Oxford University Press, 1894.
• Scott Barry Kaufman, "The Difference between ExtrAversion and ExtrOversion", Beautiful Minds, Scientific American, Springer Nature America, 2015.