Difference in root growth.

Hey everybody,
I started eight plants flowering about ten days ago. Five turned out to be males. The other three haven't really shown any signs yet, so I'm hoping for females.
The males all had massive root systems, six to eight inches out of the sides and bottoms of the cups. The three that are left, while the same size have much smaller root systems.
Is this something anybody else has noticed, or should the roots grow at the same rate for males and females?

Any thoughts?

seems to be the same rate from what i've seen but every plant has different vigor

I've never really had much opportunity with male plants to study them... I mean, who cares? They're males.