Nathaniel is an unusually verbal 3-year-old, a gentle boy who speaks earnestly, as though each word matters and each idea he wants to communicate is vitally important. And most of what he wants to talk about is trucks.
One afternoon not long ago, I sat with Nathaniel in his living room, where he explained how one of his trucks worked. "It's a front loader," he said. "But this one is special: It's an articulated front loader." He emphasized the technical term and pointed out how the truck bent in the middle, as though I, a layman, might not have known about this particular detail of construction equipment. (I didn't, in fact, but my pride as a man wouldn't let me admit it.) Then he showed me one of his backhoes. "See," he said, "the stabilizers even work!"
Next Nathaniel proceeded to pull out all his trucks. Soon the living room and dining room floors were crammed with maybe 50 vehicles, from a 2-inch-long city bus to a crane almost as big as Nathaniel himself. There were dump trucks and bulldozers, garbage trucks and tractor-trailers, and specialized vehicles for digging holes, crushing concrete, and dozens of other more esoteric tasks.
When his mom takes him on errands, Nathaniel insists they stop by local construction sites, where he'll watch the trucks for hours. He's such a regular that the workers call him by name and stop to chat about the steamrollers and Bobcats. So immersed is he in this world that if his parents call for him and he doesn't want to go, he won't say no. Instead, he'll back away issuing a loud, high-pitched "beep ... beep ... beep ... beep."
The degree of Nathaniel's interest may be unusual, but the nature of it is absolutely typical. Trucks are the universal boy toy. Tonka alone has sold 250 million worldwide since it was founded in 1947. In virtually every country you'll find boys vroom-vrooming around some sort of vehicle. A few years ago I was in a rural village in Zimbabwe where there were no cars, but the village boys had bent wire into elaborate, working models of jalopies they'd likely seen only a few times. (Similar creations, found elsewhere in Africa, are called galimoto, which means "car" in Chichewa, the national language of Malawi.)
This fascination with transport toys seems to stretch across time as well as space. At Mayan sites in Mexico, archaeologists have excavated dozens of what appear to be toys, ceramic objects with axles and wheels dating from around 1,500 years ago. There's no evidence Mayans used wheeled vehicles at all except in these toys — they had no animals that could pull a wagon. The archaeologists didn't say the toys were used primarily by boys, but I'd bet my Sears Craftsman tool kit on it.
Toying with Psychology
What is it about trucks that make them so appealing to male children? I have two daughters, so I know something about gender-related toys and obsession. Alison and Becky's Bitty Baby, Barbie, and American Girl population is only slightly smaller than that of Bangkok. The basis of the girls' interest in dolls seems obvious enough — an evolutionary drive toward maternity. But where is the parallel in boys' enthrallment with trucks? It suggests an equally fundamental human drive, but most evolutionary drives developed long before people could speak, let alone come up with a double overhead camshaft. Where, then, does it come from?
Hard to say. An enormous amount of research has been done on gender-based toy choice, but almost none of it on, let's call it vehicle adoration. The gender research tends to fall into two categories. The first simply aims to chronicle gender-based toy preferences: counting toy collections in boys' and girls' rooms, surveying toy requests in letters to Santa, watching children playing in groups.
One such study, done in 1985 by Marion O'Brien and Aletha Huston of the University of Kansas, followed children from 14 to 35 months old in a day care facility over the course of 14 months. The children were given a selection of toys: stereotypical boy toys (tools, a train, a truck), girl toys (a doll, a tea set, a playhouse), and sex-neutral toys (an hourglass, a chiming toy, stacking rings). Which ones did boys and girls mess around with most? No matter their age, kids consistently picked the toys most typically linked with their sex. Trucks and tools were first with boys; dolls with girls.
The second category of gender research accepts this male-female split in toy choice, but questions whether to pin it on how we're built (nature) or how we're taught (nurture). Gender issues, of course, are a political minefield, and the nurture argument has gained significant traction. Most psychologists now subscribe to it — with the caveat that almost none would say it's 100 percent either way. According to Dan Anderson, psychology professor and child behavior specialist at the University of Massachusetts, the consensus seems to reckon it at about 80 percent nurture, 20 percent nature, especially before age 6.
Personally, I find this ratio a bit hard to accept. My wife wore a dress at our wedding, but otherwise is strictly a jeans-and-T-shirt kind of woman. However, from the time our daughter Alison could voice an opinion, she refused to wear anything but dresses, preferably with floral prints. At one point, she even decided to change her name to Alison Flowers.
Still, nurture clearly counts. No child grows up in a hermetically sealed bubble, and the media issues a constant stream of images about "appropriate" gender behavior. You don't tend to see any girls in a TV ad for Transformers or Hot Wheels. There is also the unavoidable fact that parents buy a child's toys and, consciously or not, play into expectations too.
Kids themselves also contribute to the process. Virtually all child psychologists accept that children develop a clear awareness of sex differences and their own gender identity by the age of 2 1/2. In their study, O'Brien and Huston asked the kids to identify the gender of men and women in photos. They found that by the age of 20 months, the children were nailing the distinction. But they also found that by the age of 14 months, these same kids were consistently picking toys stereotypical to their gender. This seems to imply that they chose toys aligned with their sex before they had full awareness that there was a difference between the sexes: The effect was preceding the cause. Score one, it seems, for nature.
So, personally, I'm coming around to the idea that nature is the dominant factor. Boys like trucks because they're wired to like them. I'm backed here by a relatively new and, to some, controversial field called evolutionary psychology. Its practitioners explore human behavior via biochemistry, genetics, and other physiological elements. For example, they've found that girls born with high levels of male hormones (due to an adrenal-gland disorder) have a notably increased preference for "boy" toys and activities, and are much less drawn to "girl" toys and activities.
A striking 2002 paper on gender and toy choice in the journal Evolution and Human Behavior bolsters the evidence of biological underpinnings. Gerianne Alexander of Texas A&M and Melissa Hines of City University in London reasoned that if plaything preference is a product of biology, then it ought to show up in our close biological relatives. That is, monkeys. So they doled out toys to 44 male and 44 female vervet monkeys, all presumably safe from the pernicious influence of indoctrinating parents and clever Tonka pitchmen. The methodology for the monkeys was the same as for the kids: Give them stereotypical boy toys (a ball, a perky police car), girl toys (a pink-faced soft doll, a cooking pot), and sex-neutral toys (a picture book, a stuffed dog) and see which ones intrigue whom.
The results do not bode well for nurture advocates. The females clearly preferred the doll and pot, the males the ball and vehicle. Some females even held the doll just as they would a monkey baby, and some males were seen rolling the police car on the ground. (The study didn't say if, like Nathaniel, they tossed in dramatic siren sound effects.) This kind of cross-species analysis also colors the work of David Geary, a cognitive developmental psychologist at the University of Missouri. In his book Male, Female, Geary uses findings on brain chemistry and maturation periods to trace sexual differences in behavior in such creatures as elephant seals, bower birds, and Homo sapiens. I asked him about boys and trucks. "Boys' interest in construction toys may be related to the evolution of tool use," says Geary. "Tool making and construction of inanimate things (fishing equipment, weapons, arrows) is almost exclusively a male activity in traditional societies." Trucks and building toys also reflect "basic differences in spatial orientation, and how to manipulate objects in different ways." So Geary thinks boys' object-oriented play with trucks, blocks, and the like preps them for problem-solving tool use.
He cites a 2005 study by David Bjorklund, of Florida Atlantic University, in which 3-year-olds were shown an out-of-reach Furby or Cookie Monster and a group of tools, only one of which would help them grab the toy. If the child got stuck, an adult offered hints about the correct tool. Once the kids fetched the Furby, they tried for the Cookie Monster with a fresh set of tools, so researchers could see if they'd absorbed the underlying principle and could reapply it.
After they found the right tool, girls were just as good as boys at using it to fetch the Furby, and as good as boys at transferring the principle. But the boys chose the right tool more often without hints — 77 percent to the girls' 31 percent. The implication? Girls are equal to boys at using tools and understanding their use. But boys are more inclined to recognize a tool as the solution to a problem.
The next time I was at Nathaniel's house, he was in the middle of showing me his favorite website, implosionworld.com, where buildings are demolished with high explosives, when he sprang up and raced to the front door. The garbage truck was here and he was jumping up and down in delight. I'd seen this reaction before and had always assumed the allure was connected with the power of the engine or the scale and noise of the vehicle.
But now, with Geary's tools 'n' trucks theory in my head, I saw something else. Nathaniel was studying the truck, making mental notes about its principles of operation. It was all those moving parts: the hydraulic lifts, dumpers, compactors, and rolling bins. It was a symphony of physics, a cornucopia of contraptions. Tool heaven. That's when I decided Geary is probably right. This is what connects Fred Flintstone and Leonardo da Vinci, the Dukes of Hazzard and Steve Jobs — me and Nathaniel.