Reddit reviews Gender Development

It's tough to cite a source for something that isn't there. I seem to recall there being some discussion in Gender Development by Golombok and Fivush, though I may be misremembering that. I think the best case is to point to all of the research that's published that finds no gender differences-- in social psychology (and I would wager in most other areas, as well) it's standard practice to check for statistically significant differences by gender in all of your data. Many studies report this analysis, and state that no differences were found. Most studies just don't report it if they don't find anything. So that is to say that the vast majority of psychological and neurological research finds no gender differences at all.