Are people really free or are they bounded by invisible chains?

It really isn't a matter of our being absolutely free or a matter of being absolutely bound by "invisible chains." We do make choices in our lives but many of our choices are conditioned by our environment and social norms.

To take a fairly trivial example, in many parts of China, slurping soup or noodles and belching can be a way to show appreciation for food, but in the west it is considered extremely rude....

It really isn't a matter of our being absolutely free or a matter of being absolutely bound by "invisible chains." We do make choices in our lives but many of our choices are conditioned by our environment and social norms.

To take a fairly trivial example, in many parts of China, slurping soup or noodles and belching can be a way to show appreciation for food, but in the west it is considered extremely rude. While I know in theory that table manners are culturally contingent, the "invisible chains" of social norms instilled in me as a child still lead me to react with revulsion at people who eat noisily and chew with their mouths open, despite the fact that there are really no rational grounds for this prejudice.

There is a strong evolutionary advantage to "invisible chains" constraining on our actions. Take the example of the CN Tower in Toronto. It has a glass floor at an elevation of 1,122 feet above the ground. Despite logically knowing that it is safe to walk across it, many people panic and are unable to even step on it. This fear of heights obviously helps keep us safe, making us draw back from the edges of cliffs. It acts on a level almost prior to conscious thought. 

Often the difference between freedom and constraint is point of view. When we decide for whom to vote, where to shop, how to decorate our houses, who to date, or even what career to choose, we experience ourselves as making free choices. On the other hand, an external observer will be able, in the aggregate to predict the probable outcomes of most of these choices, based on our age, gender, and family background, and thus in that sense we are constrained.