Personality is a fickle thing.

Multitudes of factors converge, both before and after birth, to make us who we are. In the professional world, the study of these factors is one of the hottest fields of psychology, and it’s even hotter in the world of consumers—who hasn’t taken an online personality test, or given a curious click to that “What Color is Your Aura” online quiz?

The fact is that we yearn to understand ourselves. And for good reason—a greater understanding of how personality forms can help us be more deliberate about how we choose to develop our own, and even how we raise our children.

It’s common to talk about the role of genetics, class, geography and parenting style when it comes to personality, but there’s another huge factor that is too often either taken for granted, or not discussed at all: birth order.

Take a moment to consider where you fit within your own family. Are you the first-born? The middle kid? Perhaps you’re the youngest, or maybe you’re an only child. Where you fall within the hierarchy of your family has a huge effect on the development of your personality.

Let’s take a brief look at how this works.

University of Georgia psychologist Alan E. Stewart, in a field-defining 2012 work, distinguishes between what is known as “actual” birth order and what’s called “psychological” birth order. Actual birth order, as you might guess, is your actual, numerical placement within your family. Psychological birth order is your self-perceived position in your family.

Actual and psychological birth order can be different for any number of reasons, such as a large gap between the birth of siblings, a disabled sibling, or a blended family. But the important thing to remember is this: they can, and often are, very different. You’re not trapped within the role of your birth order.

That being said, let’s examine the general traits that tend to come from each of the different birth orders.

Firstborns

The firstborn child—or the one with the oldest “role” in the family—is, as you might know, the most likely to exhibit leadership skills, and to be rule and achievement-oriented.

This first child has the privilege of his or her parents’ complete attention—parents who are not already tired out from tending to the needs of siblings. This helps the firstborn start out with a better sense of self-confidence and security.

Things aren’t all rosy for the inaugural child, however. First-time parents often place all their expectations—and blame—on this child. Although he or she may receive all the attention, they may be micromanaged and critiqued at every turn, creating intense, overwhelming pressure to succeed. This can create a personality that equates love with success.

Knowing this can help parents become aware of the hopes and dreams they may be piling upon the backs of their first child, and can help that first child shake off the weight they place on themselves. Learning to relax and take life as it comes is a key skill for a firstborn child to develop.

Middle Children

The middle children often find themselves with parents who have hit their stride, and are calmer and more laid-back. They also have the advantage of having an older sibling to learn from—both from their successes and their mistakes. This can result in a child who develops quickly, both academically and socially.

They may, however, feel some jealousy toward their high-achieving older sibling who seems to soak up all the attention in the family with their constant stream of “firsts”—the first to ride a bike, to act in a play, to win an award, and so on.

The middle child may also occupy a place of invisibility in the family, as the older sibling is praised and the younger sibling is nurtured—they may find themselves alone more often than not.

If you were—or are—a middle child, remember that you are valuable, and that you have a wonderful, unique identity. You don’t have to strive to be anyone else. Just be you!

Parents of middle-children, remember that this child needs just as much attention as the others. Praise them, celebrate them, and love on them—it’s very easy to lose sight of this in the hectic day-to-day of a large family.

The Youngest

Finally, the youngest child—the baby of the family—will be pampered, nurtured, and looked after like no other, and so may develop social skills that get people to do what they want. Thus, they may be extremely charming and sociable.

These children may get away with more than their siblings, and are burdened with less responsibility, having no younger siblings to help care for. Their parents are no longer anxious about child-rearing—at this point, it’s old-hat.

Things aren’t all rosy for these kids, however. Youngest children may try harder than their siblings to differentiate themselves, and so might take a more rebellious route, getting them into trouble. Their charismatic attitudes can also tend toward manipulation if left unchecked.

For those who are last-borns, remember that life does come with its drudgery and responsibilities that must be attended to. And for the parents of these children, remember to dole out some chores—they’re not too little to do something as simple as placing plates on the table for dinner or helping fold the laundry.

No Fate But What We Make

No matter your birth order, however, you can take control of your own personality by re-thinking your role in your family. If you’re convinced that your place in your family requires you to be a leader, you’ll take on leadership qualities. If you feel that you’re the glue that socially holds the family together, you’ll take on the traits of a mediator.

Parents, teach your children to think beyond the confines of their birth-ordered role—don’t let it define who they are. Encourage them to embrace their own identities, to teach one another and avoid birth-order stereotypes. In this way, you’ll better equip your children to develop their own personality in a more intentional way.

And if you, as an adult find yourself with the negative traits of your birth order? Change it. Embrace who you are, not what you were born into. Don’t allow yourself to be controlled by random forces.

Your personality is shaped, most of all, by your own choices. So exercise your free will, be intentional, and become the person you wish to be.