what makes human beings tick

Donald Keen氏が訳した太宰治の人間失格を読み始めました。

今日取り上げるのは第一の手記の次の個所です。

Nothing was so hard for me to understand, as baffling, and at the same time so filled with menacing overtones as the commonplace remark, "Human beings work to earn their bread, for if they don't eat, they die."
In other words, you might say that I still have no understanding of what makes human beings tick.

"what makes human beings tick" の "tick" の用法を辞書で調べます。

"what makes somebody tick" で次の説明がありました。
・Oxford English Dictionary: what makes somebody behave in the way that they do: I've never really understood what makes her tick.
・Collins Dictionary: If you talk about what makes someone tick, you are talking about the beliefs, wishes, and feelings that make them behave in the way that they do.: He wanted to find out what made them tick.
・Merriam-Webster: the things that cause someone to behave a certain way : the feelings, opinions, concerns, etc., that are parts of someone's personality: I've always wondered what makes people like that tick.

"tick" だと人間も時計仕掛けのロボットの様に思えますね。