Here's what you need to know about birth order types—and how they mix, match, mesh or clash.Firstborns These children tend to be conscientious, ambitious, organized and—in relationships—dominant.If you're married to a lastborn, don't disparage what you see as his lack of responsibility. Conversely, if you're a lastborn married to an oldest child, you can learn how and why being serious can be a good idea.Middle with Middle Too bad Jan and Peter Brady couldn't marry!However, some middle children (probably for the same reasons as above) can be secretive. Beloved, treasured, and in many cases babied for much longer than their older siblings (and often by their older siblings), the stereotypical youngest of the brood tends to be less responsible and more devil-may-care, with less of a hankering to take charge. In fact, many "grow up" more quickly than kids with sibs, thanks to how much time they spend with adults, says Dr. Wondering how different birth-order pairings typically get along romantically?"That can be different if the baby of the family came after a gap of more than a few years, though," says Dr. In that case, the baby of the family may act more like an only child or an older sibling—as though the family had started all over again. Read on: Oldest with Oldest Can you say Bill and Hillary Clinton?
Onlies with Anyone Unlike the other birth-order positions, only children haven't been studied as much, says Dr. "Most people assume an only child will resemble a firstborn in relationships," since they are, after all, first, but that doesn't take into account the fact that an only never had an advisory (or bossy! An only with a firstborn can be a good match if the only child acts less classically "firstborn." And an only with the lastborn can present issues, says Dr.
Of course, a lot depends on how domineering the firstborn partner is, and how "classic" the middle child's accommodating personality is.
Remember, such variables as gender and age spacing play a role in how close your personality hews to the birth-order line, says Dr. A middle child with close-in-age older and younger siblings is more "middle-ish" than one whose younger or older sibs are years apart.
Take that into consideration and make compromises to keep the relationship solid.
Oldest with Middle This can be a fine pairing most of the time, but the middle child's tendency to mold herself around her partner may leave her in danger of not following her own dreams.