Are first-born siblings smarter, better, or cooler than their younger ones? In my family, this is a question that is often discussed around the dinner table. As a younger sibling, I passionately resent and disagree with this statement (and of course, my parents would agree!), but what does a more rigorous analysis suggest? On one hand, research suggests that first-born children enjoy more parental attention and investment. Anecdotes from parents corroborates this fact. Does enjoying more parental attention mean that first-born children are more successful than their younger ones? On the other hand, we cannot forget that first-born children are also the children to first-time parents. Younger siblings have the advantage of more experienced, mature, and possible more financially-stable parents. From these two perspectives, the jury’s still out on whether the first-born is the better sibling. Is it better to have more doting parents, or more experienced parents? Does it not matter? However, through analyzing online personality surveys, we can get a better insight on these pressing questions.
The data is from the Firstborn Personality Test from the Open-Source Psychometrics Project. In the personality test, participants were asked a series of 25 questions relating to intellect (questions mostly focus on intellect), openness to experience, extroversion, emotional stability, agreeableness, and conscientiousness. The questions that were included in the study are listed in the link I provided. Each question was on a 5 point likert scale, and the greater the total score, the more likely you are to have a “firstborn personality”.
As a preface, the survey is not making a qualitative judgement on which traits are associated “better”. What personality traits are considered “better” is a matter of personal opinion. They are simply noting whether there is a difference in personality between first-borns and younger siblings. The source of my data did do a preliminary analysis and data visualization using the data, but not more in depth methods. I haven’t seen somebody else do an analysis with this dataset in particular, but perhaps I wasn’t looking hard enough. Despite this, this topic (whether birth order has an effect on personality) is of interest to a lot of researchers. There are dozens of journal articles online investigating the same topic, however, they did not use this dataset.