Causative verbs in descriptions of people

Question

目を輝かせてアメを作っていたおじさん。
The man with sparkling eyes who made the sweets.
期待で目をくりくりさせながら...
While wide eyed in anticipation...

Both these clauses use a causative form of a verb to describe a person's eyes.

In English when we use caustive to describe a person's expression it means that they deliberately made that expression. Whereas these sentences sound like the expressions are natural/spontaneous.

1) Would these sentences be wrong if I just used the plain form of the verb? If not how would the nuance change?
2) Is there a way to know when I should use causative for something like this? It's not at all intuitive to me.
3) What other things can be described by this structure? Is it limited to eyes, facial expressions, any body gesture, an even wider scope?

Answer 1

1) 輝いた目でアメを作っていたおじさん and 期待でくりくりした目で would be understood, but they are a bit less natural.

2) I feel many of them are idioms or established set phrases, so perhaps you just have to get used to common ones.

3) It's not limited to facial expressions.

• 口をとがらせて反論する
• 鼻を膨らませながら怒る
• 期待に胸を膨らませながら考える
• 緊張で足を震わせながら報告する
• 肩を怒らせて歩く
• 首を長くして待つ (eagerly look forward)
• 息を弾ませながら話す
• 汗を滲ませながら走る

There may be similar actions which are not related to body parts, but such actions would probably be expressed with causative forms in English, too.

Answer 2

1) No. 目を輝かしアメを作る、目をくりくりしながら、both constructions are OK. By the way this くりくり usually indicates "the eyes are moving actively and/or are wide open."

2) In my opinion, there are little differences even in nuance, but the causative make the sentence a bit less "descriptive(I don't know this word make a sense)". The Japanese causative action doesn't have to be "deliberately" or not even "voluntarily" caused. e.g. 彼は癲癇(epilepsy)で手足をヒクヒクさせていた。

3) Do you mean the causative by "this structure?" If so, everything. 戦争は多くの難民を発生させた。新情報は会社の新たな行動を控えさせた。

Answer 3

Besides 目を輝かせる , a couple more such expressions come to mind:

目を細める "narrow one's eyes" (often in a good way - that is, smile kindly, look at [a baby] fondly] (ほそめる is one of those causatives made by adding める to the root of an い adjective, in this case ほそい)

耳をすます "make one's ears clear" - that is, listen carefully

I don't think any of these suggest the expression is adopted deliberately