I think perhaps intelligence may wrongly be associated with instinct since shrimps have no brains and just a developed central nervous system. heh
HOWEVER, having said that- my Malawa are definitely harder to catch than my cherries. They have a much more aggressive instinct toward food, and a more highly developed "flight" response when trying to catch them. They also have a more powerful tail flip which makes them 2 or 3 times harder for me to catch.
Perhaps Malawa (and possibly Tigers) have held on to their wild instincts a bit better than some of the more developed "domesticated" shrimp.
Then again, they could have different instincts altogether?