The article “Sensitive, Indifferent or Labile: Psychopathy and Emotions in Finnish Forensic Psychiatry 1900s–1960s” by Katariina Parhi (in open access) might be of interest to h-madness readers. The abstract on the publisher’s website reads:

“Psychopathy was one of the most common diagnoses in Finnish forensic psychiatric
examinations between the 1910s and 1960s. Abnormal categories of emotions such as
sensitivity, indifference and the tendency to shift among different emotions or labil-
ity, were among the principal symptoms of psychopathy. This paper describes and
analyses the ways in which Finnish forensic psychiatrists between the 1900s and 1930s
perceived and portrayed the emotions of individuals they considered to be psycho-
paths, and how abnormal categories of emotions persisted until the end of the 1960s.
Psychopathic categories of emotions were defined along a spectrum ranging between
the extremes of sensitivity and of coldness and included volatility, which entailed
rapid mood swings. Displaying either or both extremes of emotion defined psychopa-
thy. The unifying category of abnormal emotions disappeared when the diagnosis of
psychopathy ceased to exist in 1969, when it was replaced by the diagnostic category
of personality disorders”