As a rather science-focused person I'm kind of torn regarding this subject. I don't really think that e. g. the constellation of the planets/stars etc. at our birth defines our character traits. This being said I've met many people whose character traits perfectly go along with their zodiac sign. But I guess that's because of the following: I think that the environment that one experiences during the first days/weeks after birth influences our personality. So I guess it makes a difference whether the first experiences with the outside world as a baby are warm and sunny (like in August, leo) vs. cold and windy (like in January, capricorn). So that's in my opinion the reason why e. g. people whose zodiac sign is leo are oftentimes more bright and energetic and people whose zodiac sign is capricon are sometimes more severe.