I realize this is a strange thing to be concerned about. My cat will jump in the air to catch an insect or toy, but he doesn't jump on anything high like counters, tables, etc. He is a young cat and in good physical health. He is very active and playful. We play chase games almost every night. He is short, if you can describe a cat as short. When he does get up on the sofa, he is very tentative about jumping. He seems to try to judge it very carefully before he attempts it. Most of the time, he pulls himself up by his claws like my elderly Siamese. I've read that cats learn by watching other cats and was wondering if it is possible that he doesn't jump on things because she doesn't? Before my Siamese got arthritis, it wasn't unusual to find her on top of the refridgerator or on the highest shelf in the linen closet. My parents have an older cat that is blind in one eye, but even she jumps on their counter without thinking twice. The funny thing is, I don't want Speck jumping on the counters, especially since he gets into more mischief than 10 cats combined!