These qualities, of course, won’t disappear entirely. But as families continue to shrink and the number of middle children dwindles, there is real reason to fear. Because the irony is the strengths associated with middle children come not from parental nurturing but parental inattention. That means these virtues are especially difficult to cultivate in other kids. The secret power of middles, says Salmon, “points away from the notion that successful parenting is all about time and attention.” In advocating for middles, Salmon is also promoting the idea that today’s culture of overparenting is actually hindering the development of classic middle-child merits in all children, because middles are forged in adversity. Alfred Adler took this idea even further: He believed that firstborns, scarred by resentment at their childhood dethronement, are most likely to become authoritarians. Middle children, spurred by an empathetic sense of being overlooked, are most likely to fight injustice.

It’s possible you are a middle child and you possess none of the qualities associated with your middleborn brethren. It’s also possible you’re a firstborn, or a lastborn, or an only child, or one of 20, and you possess all of a middle child’s qualities and more. And if you’re a parent — and I say this as a parent — who is thinking of having only one or two kids, it’s very unlikely that the notion of further depleting the world’s reserve of middle children will change your considerations, if you even consider it at all. Salmon, for her part, isn’t necessarily encouraging you to have more middle children, but rather to think about your middle children — and teach them to think about themselves — differently.