This comment... 
If the child falls in the normal range... (not retarded/autistic...
and so on)... I believe that the good parenting techniques will
work well on the child. All parents should learn good parenting
techniques.
Humans on the whole, "believe in themselves" and their reasonings
(common sense).
That is most unfortunate. There are good techniques (you need to
develop skills to apply the techniques well) and parents should
learn what these are and not depend on their own reasonings or
common sense.
If what they believe is what the authorities say, then good.
Otherwise, they should have a serious rethink as to the validity of
their own "common" sense. That is contingent on the fact that they
must know what the authorities recommend.
If they disagree with what the authorities recommend, then they
must have valid reasons for disagreeing. That is why having a
logical mind and knowing the rules of logic and knowing what makes
a good argument is very important. If you decide to go with your
"common sense" based on "poor arguments" in your own head, that is
most unfortunate.
For example, a boss in a company can use his common sense in
handling his workers or he can see what the best practices in HR
Management are. If he decides to go with his common sense and he
decided on that based on illogical and poor arguments, that would
be most unfortunate.
In a small company, it might not be so important. In an big
company, the consequences can be very drastic if the best practices
of HR management are not implemented.
You cannot say, every worker is different and so, there is no need
to implement the best practices of Human resource management in the
company.
If you get an independent consultant in, he will be able to tell
the boss, "This is the consequence of doing this and that and these
are the consequences (consequences can be in the form of
opportunity costs, hidden) of not doing that.
The boss will not be able to see it because people see things from
their own subjective (inaccurate) point of view rather than an
objective (more accurate) point of view.
It is better not to trust your own perspective and change your
perspectives to those of recognized authorities in the field (need
not be people but can be a list of best practices, for
example)
Parenting involves the lives of your own children and if parents
want to mess up their children's lives, (or is tida apa about
giving the best for their own child/ren), that is the parents'
prerogative and their responsibility.
I can only urge parents to learn the techniques of good parenting
from recognized authorities rather than on their own common sense.
There are many consequences that are hidden that people do not
realize and cannot see.
