Baymax is rather calm, even when in dangerous situations, and takes his time thinking of ways out of even the simplest of situations. Baymax is also very curious of his surroundings and tends to get easily distracted.
However, after meeting Hiro, he slowly begins to change, pick up human tendencies and emotions, and eventually gains a personality of his very own, outside of his original programming, thus enabling him to form a close bond with the young boy genius, to the point where his protection over the former was no longer out of the fact that he was his "patient", but rather because he felt a true emotional connection and love for him. During his time with Hiro, Baymax saw the boy as a patient and would often follow whatever he would suggest, when believing it would improve his health, such as following the microbot to where it was heading, in addition to allowing Hiro to upgrade him twice to catch Yokai. However, as he grew close to Hiro, he no longer followed Hiro's orders, specifically after the latter manipulated the robot's programming in order to murder Yokai; growing to realize that this would not help Hiro and that Tadashi wouldn't approve, thus proving he had moved on from his initial programming. From that point, forward, Baymax's actions were consented.