In my psychology class we were assigned to look up our horoscope signs, their personality traits, and if any of them were accurate. Reading about my personality traits as a libra led me to the following theory.
According to prepscholar.com Libras are Diplomatic, fair, idealistic, social, clever, incredibly sexy, indecisive, non-confrontational, self-pitying, unreliable, and vain. I do believe that many of these match. The reason these traits apply to me is because of the way I was raised, and the environment I grew up in. Maybe that does end up correlating with the month I was born in.
My theory is that; a certain type of people procreate in certain situations that only happen in certain months. For example, nine months before October is January. During January there is typically a lot of parties, so October babies are party babies raised by party parents. These parents can be immature; maybe forced together by the situation; or amazing people who just had too much to drink at a new years eve party. I believe this could factor into why libras tend to have the same personality traits, or its all just vague nonsense, made up pseudo science, to make people feel some sense of security in a scary confusing world with no predictable fate believing in an omnipotent being that isn't God. Because why believe in God, and hold yourself accountable, when you can blame your faults on mercury being in retrograde.
If you wake up every morning to read your horoscope eventually it becomes a self fulfilling prophecy. You'll see correlations between the events of your day, and what you have read. This could be for some sense of security, something to follow, something to blame. If used correctly the characteristics of your horoscope could possibly lead to the Pygmalion effect. (also know as the Rosenthal effect).
The Pygmalion effect is what zodiac girlies call manifesting, and it does seem to work. If you tell yourself you will have a good a day, you might actually have a good day. So, maybe this works with other things as well, if you tell yourself you are smart you would start trying to prove that. If used correctly the Pygmalion effect could help people better themselves. Using the very accurate science of horoscopes and self fulfilling prophecies to create a better life for yourself. This, however, only works for certain things. Like my earlier example of saying you are going to have a good day, and then experiencing it, only works if you choose to stay positive.
My zodiac sign definitely matches me in some regards, but these features are vague and can be applied to almost anyone. I often find that zodiac signs, horoscope charts, and tarot cards become a self fulfilling prophecy. None more accurate than the other they all prey off your brains basic need to recognize patterns, an evolutionary trait designed to help humans survive.
The horoscope I had looked up only ever matched once. That Friday when I let go of a pair of pants that didn't fit anymore, turning them into a bag, the horoscope had said I would "make a new of something I once loved".