Sa tête ou la tête?

Question

Pourquoi "il avait répété dans sa tête" et pas "il avait répété dans la tête"?

Accepted Answer

Bonjour Lori, 
 
"he'd rehearsed in his head" 
I think in this query you are alluding to the way body parts are identified.
"sa tète" is appropriate here because it is a specific situation (his head) not a general comment.
https://progress.lawlessfrench.com/questions/view/using-le-la-les-with-body-parts-and-clothing-definite-articles
The above link may help you further.
Bonne continuation
Jim

Answer

In this case, I believe both are possible -- sa tête and la tête. However, using the sa tête in this case is, in fact, more common. Why? I honestly don't know. None of the rules I could find in the lessons pertains to this situation.