Clearly its in our own nature as social animals to bond with family, friends and pets. A lot of this is tied to fundamental characteristics of our species and behavior such as our cooperative social structure, maternal investment and care, etc. Because of these traits we naturally tend to see human characteristics in other animals and their behavior when the reality is that such behavior is often more instinctual or survival oriented than social.
The reality is that most reptiles have a fundamentally different reproductive strategy than mammals and their level of maternal investment, at least as far as care of their offspring is concerned, is in stark contrast. Much of our own bonding and social behaviors are tied to our reproductive strategy and the fact that our offspring are reliant on a considerable amount of care after birth in order to survive. In order to provide the required care, this often requires social cooperation with other members of our family. Most reptiles have a more primitive reproductive strategy whereby little to no post birth care is required for the offspring to survive. As a result, most reptiles lack or have limited physiological responses that cause bonding behavior and its associated emotion (yes, there are chemical changes at the physiological level that cause bonding and brooding behavior in mammals). While some exceptions are known (i.e. crocodilians, some skinks, etc.), chameleons are not believed to be an exception to this rule. Baby chameleons are able to survive on their own from the moment they are born and are not known to purposefully associate with their parents, particularly for any parent-offspring related protection or care.
In looking for similar behaviors, emotions and care in other animals as we would expect in mammals, we often misinterpret what we see. The example of the chameleon from Life in Cold Blood that gave live birth (Bradypodion pumilum) is a good example. The female in this case did not clean the offspring or wipe the offspring down with her feet as was suggested earlier in this thread. The offspring break free of their birthing membrane on their own and clean themselves up on their own. The footage of the female touching one of the babies with her feet is simply an example of the female walking over the offspring that have just been born and could have very easily been partially staged. There are various reports of live bearing chameleon species predating on their offspring shortly after birth.
Now, obviously different chameleons will respond to different people in varying ways and their response to people can change. Chameleons do learn what should and should not be considered a threat and they can learn to associate things with food, etc. In that sense their response to people, even individuals, can evolve based on their experience. Learning that their keepers are not a threat and learning to associate their keepers with food or other things, however, is not the same as affection. Often we completely miscategorize the behaviors to fit the response we want or hope to see when the reality is these are signals with completely different meanings.
Chris