When you change your baby's diaper, does he make a distressed face that seems to say, "Hey, Mommy, get your hands off my bottom," and wave his tiny fists in the air? Or does he smile and coo as if getting a new nappy is one more blissful moment in his Disneyland day? Either way, your child is giving you a snapshot of his personality. "Temperament is something you're born with, and it often remains consistent throughout your life," says Linda Dunlap, Ph.D., professor of developmental psychology at Marist College, in Poughkeepsie, New York. A recent study at the University of Iowa, in Iowa City, bears this out: Babies who were very fussy at 3 to 4 weeks old were more likely to have anxiety problems by the time they were tweens.
Still, temperament isn't set in stone. Studies at Harvard University tested to see how infants reacted to unfamiliar sights, sounds, and people, and then monitored them as they grew up. The 10 percent of babies on either end of the spectrum -- those who got very upset when exposed to new things and those who hardly reacted at all -- tended to retain their high-strung or laid-back personas as young adults. But the personalities of the roughly 80 percent of babies who fell somewhere in the middle were more likely to change over time. "Just because your 1-year-old bursts into tears at the drop of a hat doesn't mean he's going to grow up to be a kid who cries all the time," says Ross Thompson, Ph.D., professor of developmental psychology at the University of California-Davis. "As his brain matures, he may learn to control his emotions better."
While much of a baby's personality is genetically programmed, his environment also has an important influence. The way a parent responds to a child's easygoing or demanding nature can either reinforce his basic temperament or help to moderate it. Kids who go with the flow tend to get rewarded for their easy behavior. "But when a baby is difficult, his parents may say things like, 'Will you lie still so I can get that diaper on you?'" explains Kevin Leman, Ph.D., a child psychologist and author of The Birth Order Book. Taking that tone can actually make your child more defiant and argumentative.
Keep in mind that there's a positive side to every personality. Demanding babies can grow up to be driven, highly successful adults. And when a shy, clingy infant becomes more confident and independent, you may find yourself missing the snuggling from the early days.
What you can do now: If you recognize early on that your child becomes overly distressed when someone other than you picks him up or when he has to take a bath, look for ways to make him feel secure and happy. That could mean establishing a lovey to help him get through stressful transitions or giving him sponge baths instead of making him go into the tub. However, once your child is a toddler, slowly introducing him to novel situations, like a group playdate or a new babysitter, will help him learn to accept them.
No matter what your baby's temperament seems to be, it's important to avoid labeling him as such, advises Michele Borba, Ed.D., a Parents advisor and author of The Big Book of Parenting Solutions. If you constantly tell people, "Dylan's a cranky boy," they may expect your child to act that way, and your statement could wind up becoming a self-fulfilling prophecy.
Your baby's general outlook on life depends at least in part on when she joins your family. "If she's your firstborn, she has greater odds of being a high-achieving leader, such as an airline pilot, a principal, or a business owner," says Dr. Leman. And -- don't tell her younger siblings someday -- oldest kids tend to be slightly smarter as well. A Norwegian study that looked at nearly 250,000 18- and 19-year-old men found that on average those who were oldest children had an IQ three points higher than that of the next oldest sibling and four points higher than the one after that.
One big reason? You. "The oldest child gets his parents all to himself for a period of time," points out Joseph Price, Ph.D., professor of economics at Brigham Young University, in Provo, Utah. According to his research, firstborn children between ages 4 and 13 spend 3,000 more hours with their parents -- roughly an hour a day -- than each subsequent sibling does. That's because parents have to spread themselves thinner once they have two or more kids. So even if you're always around the baby, he may spend a significant chunk of that time sitting in a bouncy seat rather than sitting in your lap listening to a story.
While younger sibs may get less one-on-one time with you, they benefit in other ways. "By the time a second child comes along, you've probably become a better parent, and an older sibling often helps out by teaching a little brother or sister what he knows," says Dr. Price. Because he needs to compete for your attention, the youngest child in the family tends to be more outgoing, often developing "Look at me" skills and a class-clown personality (a long list of comedians, including Steve Carell, Jon Stewart, and Ellen DeGeneres, are the baby of their family).
Middle children often become masters of negotiation and compromise -- so they can keep the peace between their older and younger siblings and earn their busy parents' approval. And only children, who tend to spend a disproportionate amount of time in the company of adults, are usually more reliable and mature than typical kids, notes Dr. Leman. Despite the "only lonely" stereotype, growing up without live-in playmates doesn't seem to hurt their social skills any. A recent Ohio State University study of more than 13,000 teens and tweens found that singletons were just as popular as those who had siblings.
What you can do now: Make a concerted effort to spend as much alone time with your younger kids as you did with your firstborn when she was the same age. If your eldest child is playing a computer game, use the opportunity to look at books or do a puzzle with her little brother. Also resist the urge to compare your kids' development ("Gee, Betsy was already sitting up at 6 months, but Tara is certainly taking her sweet time!"). As long as your youngest is developing within the normal range, there's no need to concern yourself with whether she's advancing at the same speed.
Can you really assess the braininess of an infant who can't yet say "Dada," much less answer questions or fill in the circles on a test booklet? Experts say yes. "Babies are very good at taking in information and remembering it, which is the basis of intelligence,? says Joseph Fagan, Ph.D., professor of psychology at Case Western Reserve University, in Cleveland. From a baby's earliest days, there are signs of what's going on in his rapidly developing brain, and scientists have come up with new ways to measure it.
For example, Dr. Fagan tested how well babies are able to absorb info by letting them look at a picture of a face for several seconds. A few minutes later, he showed them the same picture next to one they hadn't seen before. Babies who quickly turned their eyes from the familiar photo to the new one were considered to be more intelligent. When Dr. Fagan gave those same children standard IQ tests years later, their scores were remarkably consistent with his initial assessments. "We can't predict who will go to Harvard one day, but we can tell if a baby's cognitive skills are developing normally," says Dr. Fagan.
Researchers are also looking at other ways to measure infant intelligence -- how easily they learn to complete simple tasks, such as kicking a mobile, the rate at which they become bored with sounds they've heard before, and even their basic understanding of solids and liquids.
Outside the science lab, there is a simple clue to look for as a parent: your child's ability to stick with a task, like grabbing for a rattle, until he masters it. "Babies who can focus on one thing for a little while without getting bored or giving up have the kind of persistence that will help them excel in school and in life," says Dr. Dunlap.
What you can do now: Assume your baby is a budding genius and treat him as such by playing hand and foot games with accompanying verbal routines, such as This Little Piggy and pat-a-cake (these will help him anticipate what's about to happen), reading books with lots of repeating phrases (which will boost his sound and word recognition), and providing plenty of stimulation. There's no need to spend a dime on brain-building DVDs. Simply chatting to your child as you go about your day and pointing out the new things you see together will help get his neurons firing.
How you talk to your child is as important as what you say. Research conducted at Carnegie Mellon University, in Pittsburgh, found that babies learn language earlier when parents speak in a high-pitched voice and use short sentences. Also give your child visual cues, such as holding a fist near your mouth to ask if he wants a bottle. "Studies show that when you use hand gestures or baby sign language, you're planting the seeds of language," says Dr. Borba.
Whether your baby is agreeable or easily frustrated, a firstborn or a younger child, or fast or slow to master new tasks, his traits are simply tantalizing hints about the child he might eventually become. "A kid's life is like a painting," says Dr. Thompson. "The initial brushstrokes begin to define it, but by the time he's in grade school, there are so many different strokes that you can't even see the early ones anymore." And whatever style that work of art turns out to be, it will be a beautiful surprise.
According to the latest scientific thinking, these are merely old wives' tales.
If your baby loves his pacifier, he'll probably be a late talker. Although speech therapists recommend phasing out pacifiers during waking hours once a child starts to talk, there's no indication that kids who like to suck are prone to language delays.
If your child has a big head, she has an extra-smart brain. The circumference of your child's noggin has nothing to with her intelligence. "The critical thing is the number and quality of interconnections between neurons," says Dr. Linda Dunlap.
If your infant wants to be held all the time, he's going to wind up spoiled. Go ahead and pick him up. You can't create an overindulged, entitled baby by snuggling him too much, and research has found that children who have a secure attachment to their parents have greater self-esteem and stronger coping skills.
If your baby turns her nose up at peas, she'll grow up to be a picky eater. Lots of babies go through fickle phases, so keep introducing new foods. "If you gently offer the same dime-size portion ten or more times, he may eventually eat it," says Dr. Michele Borba.
If your baby is an early walker or crawler, he's bound to be athletic. A child who hits his motor milestones early might have superior strength and coordination. "But he needs to have an interest in playing sports and the desire to practice," says Dr. Dunlap.
Originally published in the September 2011 issue of Parents magazine.