Pink Brain Blue Brain (Amazon) is a fascinating book, covering the research into the extent of gender differences at birth, and how socialisation, education, and play make them bigger.
Differences are very, very minor in babies (studies showing otherwise are problematic, for example, not blind). Notably, boys tend to be more fussy (more emotionally needy, despite later becoming less emotionally aware), and as they grow boys are more boisterous and physically stronger. By contrast, girls are more mentally mature, and happier to sit and read for example – they have better fine motor skills.
Boys very slightly better on some specific spatial skills, this is exacerbated by childhood play – “boy”-play encourages spatial skills (e.g. throwing balls, building blocks). “Girl”-play encourages verbal skills, and fine motor skills (e.g. playing families, colouring). The result is that girls do better at reading and especially writing, while boys do better at spatial skills, which is a component of math.
Under-estimating girls starts early, for example, underestimating how steep a slope they would be willing to crawl down (near correct for boys).
A key and really important point is that differences are heavily influenced by socioeconomic status, with fewer gender differences in higher socio-economic families, and in those that are more egalitarian families.
This makes me think, that much of the critique about Goldiblox comes from people of high socio-economic status, who are more likely to eschew traditional roles, or at least have very involved fathers (who encourage more physical play that helps girls expand their spatial awareness). This toy isn’t needed by them. One factoid in the book is that 88% of lego kits bought for boys originally. My impression is the critique comes from the kind of people who fall in the 12%.
One such point is that the toy is for adults. Well yes, because adults buy the toys. Children start off with such tiny differences, and then are socialised in such a way that they increase exponentially. This changes as adults behave differently – such as buying a pink toy that emphases spatial awareness rather than a pink toy that emphases verbal and fine motor skills. In fact need for pink blocks is explicitly called out in the book.
I agree with parts of the critique – it is mostly marketing, is isn’t complicated enough, it’s not a perfect solution. The thing is, there is something pretty close to a perfect solution – it’s hands on learning, encouraging vocalisation and reading in boys, and spatial awareness in girls. Helping with play that addresses the minuscule differences, rather than exacerbates them. But this is intensive, and expensive, and may not be an option for those that need it most.