Shape of carbon vs. column 14

bjon-07

Hi, I have a question

CH3, doublet (one unpaired electron) has a triangular planor shape.
According to vspr theory it should have a tiangular pryimidal shape. The rest of the elements in row 14 ( Si, Ge, Sn, Pb) all have a tringular pryimidal shape.

From what i understand, in carbon which is shaped like a "Y" the unpaired electron is spread out equal above and below the the 'plane' which makes up the "2D" three orbitals that take the shape of the Y.

Why dont the other elements in column 14 have this same feature. i have feeling that is has something to do with electron negativey.

thank you