It's definitely subjunctive mood. But it's not easy.
Were can work to create the hypothetical in contexts in which the main verb
(understand/comprehend/got in my modified examples) is either
present and past:
a) Parents and psychologists understand/comprehend/get the idea that if real fear and harsh punishment were removed from child training, children would develop
into better happier and kinder adults.
b) Parents and psychologists understood/comprehended/got the idea that if real fear and harsh punishment were removed from child training, children would develop
into better happier and kinder adults.
Now, in b), "if the fear were removed" can be thought of
being something valid/attempted at the time in the past or even valid/attempted at the present moment,
the latter in an attempt to make the concept livelier to the
reader, similar to the:
He told me that the Earth was round.
He
told me that the Earth
is round.