Foot binding was created with a purpose in mind. The women didn't necessarily enjoy the pain, but they enjoyed the results. As long as a bound foot was alluring to men, women would partake in the practice, no matter how harmful. But foot binding is an extreme case. It's easy for people of this century to denounce foot binding for its horrid effects on the women who practiced it. We see X-rays of bound feet and we cringe. But as was said in class, we all change our appearances in some way every day and we never think of those modifications the same way we think of foot binding. Granted, wearing a certain shirt to look more attractive doesn't warrant being put in the same category as foot binding. But what about other permanent but less painful modifications to look more appealing?
People now spend hundreds of dollars each year to modify their skin and hair. This may not happen a lot in the US, but in places like India, skin lightening used to be an issue. In my experience, there is a stigma in many former colonial countries that light skin is ideal. The lighter skinned nationals often got preferential treatment from the colonials because the lighter they were, the more "white blood" they had in them. So if your skin got too dark from being out in the sun, you needed to correct it somehow. In the modern era, natural remedies were pushed aside for laboratory devised products. Some of these products contain harsh chemicals that literally destroy the pigment in your cells and can create many negative side effects which include pain. They may not cause as much physical pain as foot binding, but the negative effects can be lasting. As with any prolonged chemical exposure, mutations and cancers can become an issue. They can even damage sensitive hair follicles in the skin or inflame nerve endings. For the most part, the use of extreme chemicals like bleach are now frowned upon and rarely used for their negative side effects. However, products still exist (even in the US) to "brighten" dark skin. The attempt to lighten still occurs, just at less extremes.
As science advances, I think these modifications will only increase and become more prevalent. As the research field expands, it now incorporates cosmetics. Stem cells are being researched for use in everything from treatment of cancers to wrinkles. Science is being used more and more to easily modify the body (think plastic surgery too). If you go to a plastic surgeon, I'm sure they would give you smaller feet for the right price. Modern medicine is making these modifications less painful. If there's no pain, what deterrent is there to stop these modifications?
But I have a question as to where to draw the line in "body modification." I think we can all agree that dying your hair from blond to black is a form of modification. But what about parents modifying or choosing an embryo that has black hair? Does that count as modification? If we say that a modification is a conscious choice by the individual to alter their body in some way, then circumcision on infants and braces on children wouldn't count because they, themselves, have no say. What's the difference between parents choosing to circumcise an infant and choosing specific physical characteristics for the infant to have? There is no physical body yet to modify in the latter but the body that emerges 9 months later was created by specific intention, as the small foot was created by specific intention.