Raising skill from default: different basic attributes

[Erling]

A character has DX 12, IQ 15 and Stealth (A) DX+4 [16]-16. He also wants to acquire Shadowing skill which defaults to Stealth-4 on foot.

Can he raise Shadowing from his Stealth-4 default, taking into account that Shadowing is based on IQ and Stealth is based on DX?

If answer is "yes", then how can he do that? Raise IQ-based Shadowing from DX-based Stealth-4? Raise IQ-based Shadowing from IQ-based Stealth-4? Raise DX-based Shadowing from DX-based Stealth-4? Raise DX-based Shadowing from IQ-based Stealth-4? In some cases default becomes kinda pointless since character's IQ score is higher than the default.

[sir_pudding]

You raise it from the default, the attribute isn't relevant. However this is a rule that rarely comes up, and I think in this case won't either. His Shadowing default is 12, which is lower than IQ-1 anyway.

[vicky_molokh]

The rules for raising things from default don't have special exceptions. You calculate your default, whatever it is, and you raise the skill from it as usual. There are no special rules for cases when the default comes from a different attribute.