How does ほど work in the 〜すれば〜するほど construction?

Question

I understand that 〜すれば〜するほど is used to mean "the more you do ~ the more ~". However, I don't see how this meaning is derived from this sentence pattern. I assume the ば is from the conditional form and ほど is supposed to mean "extent". 人が多ければ多いほど楽しい == "The more the merrier". However if we look at this from the actual construction it seems like: "If there are more people, the extent of more is fun." This may sound weird, but I can't comprehend it in terms of Japanese, am I looking at it incorrectly? Is ほど a particle in this case? A noun? Of course I can look at it and think in English "oh that sentence pattern means 'the more x the more y' and be on my way, but I would like to be able to understand in terms of Japanese grammar. Additionally, it appears in a similar construction: 人が多いほど楽しい In this construction, does it merely link 多い and 楽しい in a fashion that means if one is high, so it the other? Is it a particle in this case? Edit: To clarify, I understand the meaning and logical use of ほど in sentences such as: 彼ほど日本語がうまくない _kare hodo nihongo ga umakunai_ あいつを殺したいほど嫌いだ _aitsu wo koroshitai hodo kirai da_ These sentences make logical sense to me. "I hate him to the _extent_ of wanting to kill him.", etc. However, when it is used in sentences such as the following, ほど seems closer to 方が and I can't see the relation to "extent". 多いほど楽しい _ooi hodo tanoshii_ ~= The more the better. 早いほどいい _hayai hodo ii_ ~= The sooner the better. vs 多い方が楽しい _ooi hou ga tanoshii_ 早い方がいい _hayai hou ga ii_

Answer 1

人が多ければ - If there are many people

多いほど - to the extent that there are many people

楽しくなる。- will become more fun.

ば can be seen as a conditional which says "if and only if." So -- If (and only if) there are many people (to extent that there are many) it will be fun. The construction is providing a hypothetical, providing an outcome and showing correlation.

日本語の会話を練習すればするほどペラペラになるよ。If and only if you practice Japanese conversation, to the extent you do it, you will become fluent.

人が多いほど楽しい - It will be as much fun as there are people (?). Quasi-particle ほど is providing a limit/upper boundary. As the amount of people increases, so does the fun.