Adler’s birth order theory suggests that the order in which you are born into your family can have a lasting impact on your behavior, emotions, and relationships with other people. While there is some ...

found that birth order “does not lasting effect on broad personality traits” such as extraversion, emotional stability or agreeableness. Given this fact and that many studies have posted ...

The study found there was an observed effect of around 1.5 IQ points for each increase in birth-order position.