When our bodies realise dopamine, we feel pleasure which makes us more likely to carry out the behaviour that caused this again (and again). This works when we wear any clothes old or new as long as it has symbolic value to us. Researcher Karen Pine found that items symbolic to the wearer left them feeling much more confident.
The theory of ‘enclothed cognition’ teaches us that the attributes we associate with specific items of clothing are extremely powerful. When we wear these clothes, the associations have the power to alter the way we feel and even impact the way we act. So, for example, if you associate a yellow dress with joy, then you will embody that feeling of joy when you put it on.
Researchers found that people wearing black clothing have a larger influence on a group as they come across as more authoritative. If your end goal is to feel confident when wearing black, then feelings of happiness will surely follow. However, it is important to stress that it is all about your personal associations and symbolic value.