precocity, preciosity

Precocity or precocity describes something or someone that has matured or developed early or prematurely --
That child's precocity is unusual; he should spend more time with other children.
Early warm weather can cause precocity; but the fruit may rot before it ripens.

Preciosity or preciosity means an affectation of extreme refinement or delicacy, in speech, writing, or style --
He loathes preciosity; if she asks for the little girl's room he may make a smart remark.
Her home is filled with chintz pillows, doilies, and other bits of preciosity.

Now that you know that, you can say --
"It's not really precocity; the child merely repeats the preciosity he has learned from his mother."