Raising one's thumb to praise something-rule, a Modern or a Traditional one?

[RongYingMin]

I used to think that the rule of raising one's thumb to praise something is a rule which was originated from a certain modern western society.
But yesterday I read Smiling Proud Wanderer as I found that the thumb-raising-rule existed in the time of Ming Dynasty. In the novel, some characters used this rule to praise something interesting such as: a person's excellent kung fu skills, a person's chivalry and the like.
It turned out that this rule seems to be a traditional rule in the ancient China.

Whether what Jin Yong wrote about this rule is believable or not?

When did it appear? And from what was it formed?

Could anyone tell me pls?