by Chris Bodenner
A reader writes:
One point about the arguments you’ve posted so far: They all seem to operate from the assumption the family dynamic is a closed system absent of any outside influences. That certainly isn’t our experience. With two working parents, our daughters spend a good deal of time with the sitter and her three boys (all older than our girls). My first born might be that at our house, but she’s the fourth during the day, Monday through Friday. My wife and I are certain she modeled eating, walking, potty training and many other developmental milestones off of her weekday siblings’ examples. We are grateful for this because it made our lives much easier as first-time parents. But if someone was evaluating her birth order and the impact on her development, temperament, personality, etc. they’d get it all wrong without that additional background about her upbringing.
Thanks for the great blog. It’s a godsend for busy parents who don’t have a ton of time but still need a helpful filter and fresh perspective on the day’s news.
An expert weighs in:
There are hundreds of studies looking at the effects of birth order, mainly because it is among the easiest parameters to ask a test subject on a questionnaire. Effects ranging from long-term income to personality type get assigned to birth order. Unfortunately, most of these studies suffer from two major flaws, outlined in Welcome To Your Child’s Brain. The first issue is:
who answers the survey? If you ask family members about each other, they answer in terms of their relationships. Mothers tend to think their older children are more responsible, and their younger children are more rebellious. Well, duh – this is the relationship between siblings. In studies where the evaluator is a non-family member, these effects go away.
The second issue is more subtle: every family with children has a firstborn, but only multi-child families have later-borns. So on average, later-borns come from larger families – and therefore have fewer resources per child. Once this socioeconomic confound is removed, many more effects go away.
After all this, one remaining factor that remains significant is theory-of-mind, a measure of empathy. Younger siblings acquire theory-of-mind before older siblings, by about 6-8 months for each older sibling. Reasons might include having a sibling to emulate, or having to understand the motivations of others to compete for resources. This does not necessarily mean more intelligence – but it might mean more empathy.
The Dish 