Does Birth Order Determine Your Child's Personality?

You can bet your paycheck that your firstborn and second-born children will be different. Believe it or not, psychologists believe the secret to sibling personality differences lies in birth order.

One major factor is that parents treat their children differently based on whether they're the oldest, the middle, the youngest, or the only child, says Kevin Leman, Ph.D., a psychologist who has studied birth order since 1967 and author of The Birth Order Book: Why You Are the Way You Are.

Birth order also influences a child's position in relation to their siblings, which can affect their character, adds Meri Wallace, a child and family therapist for over 20 years and author of Birth Order Blues. "Each position has unique challenges," she explains.

Here's what parents should know about birth order personality traits for oldest, middle, youngest, and only children.

Firstborn Personality Traits

Simply by being a first child, the oldest sibling will naturally be raised with a mixture of instinct and trial-and-error. This often causes parents to become by-the-book caregivers who are extremely attentive, stringent with rules, and overly neurotic about the little things. This parenting style, in turn, may cause the child to become a perfectionist, always striving to please their parents.

Firstborns tend to bask in their parents' presence, which may explain why they sometimes act like mini-adults. They're also prone to being diligent and wanting to excel at everything they do. As the leader of the pack, firstborns often tend to be:

• Reliable
• Conscientious
• Structured
• Cautious
• Controlling
• Achievers

Firstborn strengths

Since they have their parents to themselves before siblings arrive, the firstborn is accustomed to being the center of attention. "Many parents spend more time reading and explaining things to firstborns. It's not as easy when other kids come into the picture," says Frank Farley, Ph.D., a psychologist at Temple University in Philadelphia, who has studied personality and human development for decades.

"That undivided attention may have a lot to do with why firstborns tend to be overachievers," he explains. In addition to usually scoring higher on IQ tests and getting more education than their siblings, firstborns tend to outearn them.

Firstborn challenges

Success comes with a price: Firstborns tend to be type A personalities who never cut themselves any slack. "They often have an intense fear of failure, so nothing they accomplish feels good enough," says Michelle P. Maidenberg, Ph.D., a child and family therapist in White Plains, New York. And because they dread making a misstep, oldest kids tend to stick to the straight and narrow: "They're typically inflexible—they don't like change and are hesitant to step out of their comfort zone," she explains.

In addition, because parents give firstborns a lot of responsibility at home—whether it's helping with chores or watching over younger siblings—they can be quick to take charge (and can be bossy when they do). That burden can lead to excess stress for a child who already feels pressure to be perfect.

Middle Child Personality Traits

When a second child comes along, parents might raise them with less of an iron fist due to their previous experience. They might also be less attentive since there are other children in their lives. Therefore, the middle child is often a people-pleaser due to the lack of attention they get compared to older siblings and younger siblings.

"The middle child often feels left out and a sense of, 'Well, I'm not the oldest. I'm not the youngest. Who am I?'" says Wallace. This sort of hierarchical floundering leads middle children to make their mark among their peers since parental attention is usually devoted to the beloved firstborn or baby of the family. What's more, "middle children are the toughest to pin down because they play off their older sibling," says Dr. Leman.

In general, middle children tend to possess the following birth order personality traits:

• People-pleasers
• Somewhat rebellious
• Thrives on friendships
• Has a large social circle
• Peacemaker

Middle child strengths

Middleborns tend to be go-with-the-flow types. That's because, once a younger sibling arrives, they must learn how to constantly negotiate and compromise to "fit in" with everyone. Not surprisingly, Frank Sulloway, Ph.D., author of Born to Rebel: Birth Order, Family Dynamics, and Creative Lives, notes that middle kids score higher in agreeableness than both their older and younger sibs.

Because they receive less attention at home, middles tend to forge stronger bonds with friends and be less tethered to their family than their siblings. "They're usually the first of their siblings to take a trip with another family or to want to sleep at a friend's house," says Linda Dunlap, Ph.D., professor of psychology at Marist College in Poughkeepsie, New York.

Middle child challenges

Middle kids once lived as the baby of the family until a new sibling dethroned them. Unfortunately, they're often acutely aware that they don't get as much parental attention as their "trailblazing" older sibling or the beloved youngest. That realization can make them feel like their needs and wants are ignored.

"Middle kids are in a difficult position in a family because they think they're not valued," says Dr. Maidenberg, "It's easy for them to be left out and get lost in the shuffle." And there is some validity to their complaint.

For example, research has found that parents do not provide later-born children with the same cognitive support as they offered firstborn children, relaxing what they deem non-essential parenting support.

Youngest Child Personality Traits

Youngest children tend to be the most free-spirited due to their parents' increasingly laissez-faire attitude toward parenting the second (or third, or fourth, or fifth) time around. As a result, the baby of the family tends to have the following birth order traits:

• Fun-loving
• Uncomplicated
• Manipulative
• Outgoing
• Attention-seeking
• Self-centered

Youngest child strengths

Since parents generally don't have their eyes as glued to lastborns as their firstborns, the youngest sibling might develop their own ways of winning attention. They tend to be natural charmers with an outgoing, social personality; no surprise then that many famous actors and comedians are the babies of their families. In addition, youngest children tend to score higher in "agreeableness" on personality tests than firstborns, according to Dr. Sulloway's research.

The youngest also make a play for the spotlight with their adventurousness. Therefore, free-spirited lastborns may be more open to unconventional experiences and physical risks than their siblings.

Youngest child challenges

Lastborns are known for feeling that "nothing I do is important," Dr. Leman notes. "None of their accomplishments seem original. Their siblings have already learned to talk, read, and ride a bike. So parents react with less spontaneous joy at their accomplishments and may even wonder, 'Why can't they catch on faster?'"

Lastborns may also learn to use their role as the baby to manipulate others to get their way. "They're the least likely to be disciplined," notes Dr. Leman. Parents often coddle the littlest when it comes to chores and rules, failing to hold them to the same standards as their siblings.

Only Child Personality Traits

Being an only child is a unique position. Without any siblings to compete with, the only child monopolizes their parents' attention and resources—not just for a short time like a firstborn, but forever. In effect, this makes an only child something like a "super-firstborn."

In addition, only children have the privilege (and the burden) of having all their parents' support and expectations on their shoulders. Thus, only children tend to be:

• Mature for their age
• Perfectionists
• Conscientious
• Diligent
• Leaders