Hm.. I woun't dispute INTp's are wont to have motivational issues, but to say they are the most lazy of types seems to be too one-dimensional a stance. My INTp father can seem inclined to spend his free time on frivolties and unproductive wanderings, but once one gets him started on manual work or menial intellectual tasks, he is damn near unstoppable. At such times his focus and dilligence are a sight for all to see.

Also while he is by no means a natural born leader he maintains himself very well in management position and has persisted at this for about a decade now.