"Twins don't usually follow typical birth order roles," says Nancy Segal, PhD, twins expert and author of Indivisible by Two: Lives of Extraordinary Twins (Harvard University Press). "Most parents tend to be very fair and not emphasize order of birth, at least in Western nations."
However, when twins are born vaginally, the firstborn is usually bigger, and the second-born has a greater risk for health problems. In these cases, parents may unconsciously treat the first twin more like a firstborn. Elizabeth Lyons, author of Ready or Not ... There We Go! The REAL Experts' Guide to the Toddler Years with Twins (Finn-Phyllis Press, Inc.), sees this phenomenon with Jack and Henry, her 5-year-old twins. "Jack (28 minutes older) has always cared for Henry -- he's gotten him whatever he needed, communicated for him -- and he's continued with that role all the way through."
Out of Order
"Many things contribute to human behavior," says birth order expert Frank Sulloway, PhD. "Birth order only explains a small chunk." Here are some other factors that alter traditional birth order roles:
- Gender. Being born first doesn't necessarily guarantee firstborn status. In some cultures, a boy may be treated like a firstborn even when he has four older sisters, because he?s the firstborn male.
- Age differences. Birth order effects are strongest when siblings are two to four years apart. With large age gaps, siblings might act more like only children or firstborns. Siblings separated by fewer than two years are almost like twins. "When sibs are close in age, there's a physical equality," says Sulloway. It's hard to grab that truck from your younger brother when he's not all that little.
- Special-needs sibling. When a child is born with special needs, younger siblings may take on the firstborn role.
Leman recommends spending one-on-one time with each child. "Siblings compete when they're together," he says. Spend 15 minutes a week alone with each of your children, and you'll find out who they really are.