My favorite part of Halloween is the fact that it gives everyone license to dress up and be someone else for the whole day. We can shed our inhibitions and free ourselves of the preconceived notions others might have about us. The costume a person picks has two main implications. One: it reflects their innate personality. People choose what to be based on what they like and characters with which they strongly relate. On the other side of the coin however, what costume a person wear can also impact how they feel and behave while disguised by it.
Although it's extremely unlikely that clothing alone can literally alter an individual's inherant personality, it's commonly accepted that what a person wears and how it makes them feel has a direct effect on how they might behave.
For instance, it's not uncommon, for a shy person to choose a bold costume like that of a super hero and while wearing that costume become more outgoing and assertive. The psychology behind this phenomenon is complex and beyond the scope of this simple article. However, what we wish to impress upon people is that Halloween and the act of wearing costumes offers everyone a chance to explore hidden facets of their personality. Perhaps even a way to fascilitate long term positive changes.
So next time you're trying to decide what costume to pick, think about who you are and also about who you want to be. Not just for Halloween, but every day.