History/usage: 耦 vs. 偶?

Question

According to the ABC dictionary 耦 means:

a couple

as a noun and

to couple

as a verb.

Think of words like:

去耦

meaning decouple.

But, 配偶 can also be written: 配耦.

What is the history and usage of 耦 vs. 偶?

Answer 1

In terms of historical usage, the word meaning likeness, couple (Zhengzhang: /*ŋoːʔ/) was first written as「禺」as a phonetic loan, then

• Had「亻」added to it to differentiate this meaning from the other meanings written「禺」;
• Had「耒」added to it to specifically indicate the meaning two people plowing fields.

My speculations: Since the word represented by「耦」is related to「偶」(in fact, identical, just written with a different glyph for a specialised circumstance), they became interchangeable to a very large degree.「耦」was even used for the word idol:

• 木耦
• 土耦
• 耦人

The current spelling would then be just dictated by educational committees, as historically they were the same word written with two different glyphs and frequently mixed up in usage.

Answer 2

This is how Chinese characters come from. A Chinese character may have only one meaning at the beginning, later it may have some new more meanings, the different meanings are divided into seperated characters, and then the number of Chinese characters are increasing more and more. In the process of creating new characters, the characters that mean the same thing may be written in different ways, called variants, and these variants versions may exist for a long times, and some of them may be discarded or rarely used in history. In today's simplified Chinese, there are characters that have the same meaning but are written differently that may be used in different scenarios, like 耦 is used in electromagnetism only, and some that are common to each other, like 唯一 equals to 惟一.