Aside from keeping warm, the function of clothing is to identify the cliques to which a person belongs.
First, an analogy. Another proud, marginalized subset of society is metalheads. They wear the same clothes so often that a black T-shirt with complicated death-themed patterns might as well be a uniform [sic]. Bands wear this uniform on stage so you won’t be surprised when their low strings are palm-muted and their solos are intricate and virtuoso.
Clothing is like an opening statement in real-life communication. Most people dress to identify themselves with a subgroup of their culture, E.g. Outdoor athletic wear for SWPLs, baggy shirts for poor whites, suits for serious-minded men, red for Bloods, etc. This is a semiconscious, nonverbal type of communication.
Combining this with the newly christened first principle, we have an interesting application. If you want to form a new habit or assume a new attitude, you should change your appearance somehow. I can’t help wondering if this is the origin of the saying “put on your thinking cap”. So much of the thinking I do these days is rediscovery.
On an unrelated note, the conversation in the comments of the referenced post is a fascinating case study.