They are the same species, yes, their DNA has been tampered to make them more tame for Jurassic Park, yes. But the claim has been that because of this, they are...well....TWL made this claim rise
I think the raptor's adapted to the enviroment. The Isla Nublar raptors have been training them selves to break out. Robert Muldoon from JP1 said the raptors tested the fenses when feeders came. The raptor in the beginning attacked when the feeders and gaurd least expect, most likely learning the routine for the best time to strike. When they opened the door, well, details are sketchy around that...but there is still a chance they learnt that too
The Isla Sorna raptors were already free and no need to do the above. It doesnt mean they are less intelligant than the nublars
Sources: JP1, JP websites such as JPL and some excerpts from the book