1. Although the zodiac descriptions for my sign matches me for the most part, but there are some people with the same zodiac sign where it doesn't fit them. So it would be biased to only go by the times that the zodiac signs fits someone while ignoring all the times that it doesn't especially since the latter would go towards validity.
2. I personally know someone who was born on May 29 so he's a Gemini. Gemini are supposed to be outgoing, extraverts, unstable ("spontaneous" may be a nicer way to put it

My theory on astrology is that the traits that are described for personality and character usually go together as a package so-to-speak(based on experience). S of course, if one of the characteristics of say a Scorpio, is to be passionate, then you from experience you can come up with other traits that would be compatible with that and fit that into a common-sense personality/character package. My collection of personality/character traits just happens to fit my zodiac sign.
For debate:
1. Is astrology accurate when it comes to personality, character, etc.?