Did birth-order affect your personality? No.
“Reluctant to give up their belief in birth order, some theorists have instead given up their faith in standard self-report personality tests (see “Why Did Sulloway’s Results Differ From Those of Ernst and Angst?” forthcoming on this website). They’ve claimed that these tests are invalid — that they are inaccurate or insensitive measures of personality (Kagan, 1998; Sulloway, 1998, 1999). This is like blaming the yardstick when one’s theory of why some kids are taller than others fails to be confirmed. Standard self-report personality tests are the yardstick that produced the results we are trying to account for!”
From a post by psychologist, Judith Rich Harris.
While she was at it, she blasted another taboo: Whether parents love one child MORE than another. Yes.
“As everybody knows, parents don’t treat their kids all alike. And one of the things that makes parents treat their children differently — this is something that Lois Hoffman and Dunn and Plomin agreed on — is birth order. Firstborns and laterborns have different experiences in the home, right from the start. Firstborns are born to inexperienced and anxious parents, laterborns to veterans. Firstborns have their parents all to themselves for a while and then are abruptly dethroned by a rival; laterborns always have to compete for their parents’ attention. Parents give firstborns more responsibility; they give laterborns more affection.
That’s right: it’s the younger child who gets more affection. Two studies (Dunn & Plomin, 1990; McHale et al., 1995) have shown that at least half of parents with two children admit to loving one better than the other, and a large majority of these parents — more than 80 percent — say they love their younger child best. These are big differences in parental affection. If being loved more by their parents made children less aggressive (or more aggressive), then we should see birth order effects on aggressiveness. But the teachers in Deater-Deckard and Plomin’s (1999) study did not judge younger siblings to be any less aggressive (or more aggressive) than older siblings.”
I’m an oldest child of three, so I laughed pretty loud at this one. It also reminded me why I prefer dogs…