All of the analysis, arguments and evidence have been compiled in this report to establish that, as a minimum and contrary to the sensationalist headlines and extreme claims it has not been conclusively proved that birth order has no effect on personality, character or career.
Indeed, much of the evidence suggests quite the contrary—that as countless researchers, common sense, history, cultural and sociological phenomena suggest, birth order—at least in combination with other variables—has had and continues to have effects on much more than the debate about it and the personalities of those debating it.
Why Such a Big Deal About the Big 5?
But what about the psychological, personality impact of culture, socioeconomic class, etc., of origin on the significance of birth order or probability of having any siblings, e.g., in societies heavily biased toward having, favoring, pampering or "spoiling" males as firstborns or onlyborns—even to the extent of practicing female infanticide?
More importantly, are we to equate absence of an impact of birth order on the "Big 5" personality factors of extraversion, emotional stability, agreeableness, conscientiousness, or imagination with absence of an impact on anything directly or indirectly related to (including correlated with) personality?
