Recent psychological studies indicate that if children

I need to add something to your explanation of the if clause. What you said is correct, but it is not always valid. What you said is true when some sort of decision is involved, this is called real conditional. However, when you are stating a pure fact, you do not need the "will," this is called zero conditional. Let me give you an example:

1) Phosphorus burns if you expose it to the air

As you can see, we haven't used "will" because we are stating a pure fact.


As for the explanation regarding "quicker" or "more quicker", this is what the OE says:


The rule for Comparisons is that the comparison must be of comparable items and must be balanced.
In this case the comparison ‘quicker than’ could only apply to the children.
It would refer to their speed.
This is not the intent of the sentence.
The correct comparison should compare the development of the children.
Therefore the correct comparison should be ‘more quickly than’

However, to me, "more quickly" or "quicker" means the same thing so I'm still lost and can't differentiate their logical meaning. I would need your help in clarifying it!
thanks