The same idea applies to humans. We cannot willfully make ourselves turn pale or even blush but if our emotions or physical circumstances call for it, we will blush or look as if all the blood has run out of our faces. So many things are out of our conscious control. We cannot beat our own heart or demand that our pancreas secrete hormones. Most of what we do actually happens to us, as the Universe works through us. We just think we are in control.
The Universe is a huge dance of many mysteries and secrets that humans are always trying to decipher so we will feel that they we are in control. But so many things are out of our control. Squids, chameleons, and humans all are under the sway of the Laws of the Universe and only a few things are within our conscious control. Moral choice is one of them (but could also be unconsciously conditioned by culture and upbringing).
You may say, the squid is consciously deciding to eat that small fish over there and therefore it propels itself towards it to gobble it down. Yes, but what is propelling the squid to do this? It is not saying to itself, “I am going to move all my legs by stimulating their nerves with my ganglia to eat that tasty-looking minnow.” The same is true for humans. If you had to consciously tell each arm, leg, finger, hand, to move towards some food, it would take hours.
We are propelled to perform most of our actions for the sake of our survival, just as with the animals who magically change colors. It is one of the fantastic attributes of the Universe that it doesn't have to be so incredibly colorful and beautiful to continue the dance of survival. It just is.