Is Freuds theory of negation testable and does it survive testing? Freuds body of work not only provides a basis von clinical practice, but is also often quoted in social sciences and social philosophy. I recently came across a text that references Freuds concept of Verneinung (Negation):


  Ein verdrängter Vorstellungs- oder Gedankeninhalt kann also zum Bewusstsein durchdringen, unter der Bedingung, dass er sich verneinen lässt. Die Verneinung ist eine Art, das Verdrängte zur Kenntnis zu nehmen, eigentlich schon eine Aufhebung der Verdrängung, aber freilich keine Annahme des Verdrängten. [...]. Mit Hilfe der Verneinung wird nur die eine Folge des Verdrängungsvorganges rückgängig gemacht, dass dessen Vorstellungsinhalt nicht zum Bewusstsein gelangt. Es resultiert daraus eine Art von intellektueller Annahme des Verdrängten bei Fortbestand des Wesentlichen an der Verdrängung.
  
  A supressed element of thoughts or imaginations can surface in the conscious mind under the condition it can be negated. Negation is away of acknowledging the supressed, actually a repeal of the supression, but of course not an acceptance [...] By way of negation only one consequence of the supression is undone, that the content of the supressed does not become conscious. The result is a kind of intellectual acceptance of the supressed, while the supression mostly persists.


(German text wikipedia, translation mine)

Now my question is, is this aspect of negation testable (=falsifiable) in some way? What where results of such tests, if any? Absent tests that would satisfy a positivist, is there a body of experience from clinical practice that supports (or not) this theory of negation?

I'm aware that there's a lively debate about inhowfar psychoanalysis is  science or pseudoscience. Much of psychoanalysis is not falsifiable, but this specific aspect may be.
The correct translation of Verneinung in English is denial. Roy Baumeister, Karen Dale, and Kristin Sommer (2002) have reviewed empirical evidence for (or against) seven of Freud's defense mechanisms and have found that "denial [has] been amply shown in studies". You can read about the findings in detail in the article itself, which is currently avialable online here.



Source:


Baumeister, R. F., Dale, K., &amp; Sommer, K. L. (1998). Freudian defense mechanisms and empirical findings in modern social psychology: Reaction formation, projection, displacement, undoing, isolation, sublimation, and denial. Journal of Personality, 66(6), 1081-1124. doi:10.1111/1467-6494.00043