If you actually read my posts you would know

These kids didn't look at the statue. They simply took the pose they ASSUME a thinker would.

Another proof that that's the natural pose most humans would take to support their head when thinking.

Hand on chin is more of a "dramatic" thinking pose. It's an exaggerated one, that you often see in comics or theater or paintings. Like with this statue.

But in case you didn't notice it, people in comic books or statues don't have "natural" poses. They have dramatic exaggerated ones.

It's especially clear in classical sculptures. No normal human would ever pose like these statues in real life. It's more like theater.