Does slow mean very disinterested here?

Does "slow" here mean "so lacking in interest as to cause mental weariness"?

Context:

the residents an educational programme about mental illness. They found such a
hostile reaction that they were forced to discontinue the study. Nunnally (1961)
concluded that the lay public was not so much misinformed as uninformed about
mental illness, but semantic differential tests suggested that their attitudes towards
the mentally ill were very negative: 'the average man generalizes to the point of
considering the mentally ill as dirty, unintelligent, insincere, and worthless'
(1961,p. 233). Another early study by Shirley Star was unpublished but was much
quoted and imitated (Star, 1957). She created a series of vignettes representing
various mental illnesses, and found that the lay public was very slow to label any
kind of behaviour as mental illness. Both her study and that by Cumming &
Cumming found that lay people tended to define mental illness as being in hospital
or receiving treatment rather than in terms of abnormal behaviour.