Place a baby boy and girl side by side and most likely the girl would seek a face to look at, while the boy’s eye would be caught by something in motion, like a mobile. This is just one difference between the sexes, many of which begin even before birth.
Beginning at birth, girls are slightly shorter and weigh slightly less than boys. But the differences are much more than that.
“Girls’ skeletal systems are more mature, making them slightly more resistant to skeletal injuries,” says Kimberly Parker, a registered nurse and early childhood expert at Children’s Healthcare of Atlanta. “Boys are not only more physically vulnerable during the first year of life, they are more physically active with behaviors like squirming, kicking and wiggling, which may lead to more accidents.”
As the mom of two boys and one girl, Lori Harasem of Lethbridge, Alberta, Canada, noticed considerable differences. “The boys walked sooner and were climbing on things, but I had both assessed at speech therapy because their speech seemed so delayed,” says Harasem. “My girl is 18 months and was assessed yesterday and is way ahead in speech. [But] she walked later than the boys and has never climbed like they do!”
Boys and girls also experience the senses differently. “PET scans and fMRIS have detected more than 100 differences between the male and female brain and this type of research is in its own infancy!” says Adie Goldberg, coauthor of It’s a Baby Boy! (Jossey-Bass, 2009) and It’s a Baby Girl! (Jossey-Bass, 2009). “Males and females demonstrate differences in sight, sound, smell and touch sensitivity within the first few days of birth. The male most sensitive to touch in the newborn nursery is less sensitive than the least sensitive female.”
Sight is also different between the sexes. “Girl babies are better able to perceive differences in color and texture,” says Parker. “This perception may be one reason why girls will typically prefer toys with patterns and textures, such as dolls with clothing, hair, etc. Girls can also differentiate individual faces, and may actually prefer to examine the human face over other activities. Additionally, within the first six months of development, girls tend to become more sociable and more inclined to ‘coo’ at people and recognize familiar faces.”
Each sex has its own unique strengths and weaknesses. “Boy babies are better able to discern location, direction and speed of moving objects,” says Parker. “Boys will typically prefer toys that move such as trains and trucks. By 2 months of age, boys are able to see greater distances than girls, but are less able to distinguish specific details. However, boys are better able to keep track of motion, and may prefer mechanical motion over human motion. Recent research supports that boys are able to figure out the laws of motion about two months faster than girls (if you roll a ball under a couch, it will appear on the other side).”
Goldberg relates that a baby’s brain, essentially the body’s CEO, operates under a different set of construction plans depending on whether it’s male or female. “As a result, boys and girls will process information differently, perceive the world differently and in the end, respond with different behaviors,” she says. “These temperamental differences affect toy choice, movement and play!”
Some of the physical differences between the sexes involve health in general. “Girls are generally healthier than boys overall in early infancy and childhood,” says Dr. Greg Plemmons, pediatrician with Monroe Carell Jr. Children’s Hospital at Vanderbilt in Nashville, Tenn. “Girls who are premature infants fare better than premature boys. In addition, boys are more likely to be hospitalized for bronchiolitis (a common illness in infancy) as well as wheezing and asthma.”
Is it nature or nurture that determines the social and behavioral differences in the sexes? “There has always been a huge debate over whether nature or nurture has the greatest impact on a child’s development,” says Parker. “From 1924, when Freud wrote, ‘anatomy is destiny,’ to the 21st century of genome mapping and Web surfing, there has never been a clear understanding of how personalities and behaviors are shaped by genetics and environment. The bottom line is, they both have a huge impact.”
Most parents with children of both sexes will tell you there’s a distinct difference, even when parents make a conscious effort to treat both sexes equally.
Dorothea Hover-Kramer of Port Angeles, Wash., is the mother of four children, two of each sex. She says that she noticed no differences in their in utero behavior. “After birth, however, it was clear the boys wanted more food and were much more active than the girl infants,” she says. “Play began early as they were all unusually lively children. The boys placed blocks on top of each other to build towers while the girls, without any prompting, placed blocks next to each other as if to make a house or room. The girls chose dolls over other toys while the boys liked things that moved better than dolls or animals.”
Social skill and emotions manifest differently also. Elaine Masters’ son was in a weekly playgroup from about 8 to 18 months of age. “As the only boy, all was well until he was about 13 months old,” says the San Diego, Calif., resident. “At that point his favorite playmate, parallel playing, was a little girl – one of the most active in the group. Josh soon started banging on things, making more noise than the other kids (all girls) and getting a little more aggressive. I realized that he needed to start playing with more boys and how it made a difference with how I also related to the other parents once he did.”
Parker says there is no question that even newborn boys and girls exhibit physical and emotional differences. “Baby girls are generally more active in a social sense and tend to advance in areas of language skills, fine motor skills and recognizing and responding to emotion,” she says. “Baby boys, however, tend to be more active in an autonomous sense and are aggressive in play and more advanced in understanding movement and space. Many of these behavioral and learning differences may be partially explained by some basic physical differences at birth.”
Finally, it’s a common belief that girls are more emotional than boys, but Parker says even very young boys tend to have stronger emotions than girls. “They may be more easily agitated and have a harder time self-soothing,” she says. “Even when infant boys appear as calm as the girls in the face of the same frustration, baby boys’ measures of heart rate and breathing may be increased, indicated a feeling of greater distress.”
Don’t forget, though, that with all the differences between the sexes, babies are uniquely individual. “Just as there is variation between the genders, there is tremendous variation within gender,” says Goldberg. “There are girls that are feminine and chatty and girls who are physically competitive. There are boys who are quiet and artistic and boys who run through the store like the proverbial bull moose. There is no average boy or girl. Parenting is an adventure in getting to know which type of boy or girl your son or daughter is! Enjoy the journey!”