More Dads Buy the Toys, So Barbie, and Stores, Get Makeovers Barbies are for girls and construction sets are for boys. Or are they? For the first time in Barbie's more than 50-year history, Mattel is introducing a Barbie construction set that underscores a huge shift in the marketplace. Fathers are doing more of the family shopping just as girls are being encouraged more than ever by hypervigilant parents to play with toys (as boys already do) that develop math and science skills early on. It's a combination that not only has Barbie building luxury mansions - they are pink, of course - but Lego promoting a line of pastel construction toys called Friends that is an early Christmas season hit. The Mega Bloks Barbie Build "n Style line, available next week, has both girls - and their fathers - in mind. "Once it's in the home, dads would very much be able to join in this play that otherwise they might feel is not their territory," said Dr. Maureen O'Brien, a psychologist who consulted on the new Barbie set. Consumer surveys show that men are increasingly making the buying decisions for families, reflecting the growth in two-income households and those in which the women work and the men stay home. One-fifth of fathers with preschool-age children and working wives said they were the primary caretaker in 2010, according to the latest Census Bureau data. And 37.6 percent of working wives earned more than their husbands in 2011, up from 30.7 percent 10 years earlier. "Kids are going to grow up with dads that give them baths and drive them to soccer and are cutting up oranges for team snacks," said Liz Ross, president for North America of BPN, part of the IPG Mediabrands holding company, which recently completed a study on male consumers. What will go away, albeit slowly, is the image or the perception of the befuddled dad. The change is having consequences beyond toys. Consumer products have traditionally been marketed to appeal to women, and stores have been designed for women's sensibilities. Now, some brands and stores are catering directly to male decision-makers. Sears is reorganizing stores to put tools next to work wear, for instance, based on men's preferences. Procter & Gamble is working on men's grooming aisles at top retailers, a nod to the fact that women are no longer choosing shampoos or shaving creams for their husbands. With the selling point that it helps girls develop spatial reasoning, the Barbie set, a joint effort of Mattel and the toy company Mega Bloks, is also meant to pique fathers" interest. "Dad is a bigger influencer in terms of toy purchases over all, and this sets up well for that, because the construction category is something Dad grew up with and definitely has strong feelings and emotions about," said Vic Bertrand, chief innovation officer of Mega Brands, Mega Bloks" parent company. Construction sets for girls are a speedy growth category, thanks to Lego's introduction of its Friends line in January. Despite criticism that those sets were sexist - themes include a beauty shop and a fashion studio - Lego's chief executive said in August that the company sold twice as many of the sets in the first half of the year as it had expected, and retailers like Amazon and Target have named them hot holiday toys. Anne Marie Kehoe, vice president of toys for Walmart U.S., said that, with the Barbie addition, construction toys aimed at girls will represent about 20 percent of the toy construction category by the end of this year, while last year there were just a handful of products. Research shows that playing with blocks, puzzles and construction toys helps children with spatial development, said Dr. Susan C. Levine, chairwoman of the psychology department at the University of Chicago and co-principal investigator at the National Science Foundation's Spatial Intelligence and Learning Center. Even controlling for other skills such as verbal and numerical skills, she said, children with better spatial thinking are more likely to eventually go into mathematics, engineering, science and technology. She said that a set aimed at girls could be beneficial, if only because it might increase girls" likelihood of participating in construction activities. Dr. O'Brien, the consultant on the new Barbie set, said adults had traditionally been "the limiting factor" in why girls have not played with those toys as often. Recently, she said, there has been a shift in attitudes, as parents study research on development and spatial play. "For this particular product, one of the advantages is you can appeal to both moms and dads," she said of the construction set. During her research, Dr. O'Brien said, she watched a grandfather jump in to explain building principles to his granddaughter, who was playing with the Barbie. Still, the construction set is not exactly dump trucks and dirt. It remains "unapologetically all girl," said Stephanie Cota, senior vice president of global marketing for Barbie, girls" brands and games at Mattel. The Mega Bloks building pieces are pink (Pantone 219, the signature Barbie color), and the construction choices are scenes like a fashion boutique, a mansion and an ice cream cart. Each set comes with a small Barbie figure that can be snapped into the scene. Mattel, the world's largest toy maker, still leans heavily on Barbie, one of its most popular and longest-running franchises. However, pressure to update Barbie has been high - Mattel has introduced Barbies with video cameras and digital cameras in recent years. Yet sales of Barbie in North America through September fell 1 percent, even as sales of Mattel's other girl brands, like Disney Princess dolls, rose 44 percent. Mega Brands makes just a fraction of what its larger rival Lego does, and had revenues of about $376 million last year. The Barbie brand, which tends to raise feminists" ire for its overly sexualized dolls, not to mention the 1992 version saying "Math class is tough," has already taken some high-arched steps toward gender equality. A computer-engineer Barbie was introduced two years ago, for instance, with the support of the Society of Women Engineers. This time, though, the introduction appears to be a response more to market changes than to critics. Girls "don't necessarily care about, "That's a boy toy; that's not for me," " said Ms. Cota of Mattel. Now, more so than ever, girls are looking at what's fun, what they like.