How much time is devoted to you in your early childhood years is also a major effect on your achievement level. There are factors that determine this like sibship, race, sex, social status, and economic status. Father's occupation was held constant. Results Educational attainment seems to be greater among first-borns. Sibship size affects educational achievement more than the other variables.
Females tend to be smarter whether they are first-born or last born.
Marital status, birth order, and number of siblings were also related to self-esteem, although differently for males and females. Parental affection, grades, income, and marital status were related to shame. Research on birth order and family dynamics is contradictory. It's important to assess family relations and academic performance as they relate to birth order. Firstborns were more satisfied with their families and rated them as more cohesive, but later-borns had higher GPAs.