As the title Invisible Women makes clear, Perez wants to illuminate the cost of equating men with all humans. Gender neutrality is a myth; the reliance on the male default produces a system biased against women. When the male body and its needs are the standard in product design, architecture, medicine, city planning, workplace conditions, and work schedules, women’s needs are not accommodated, or they are given very low priority. Moreover, because the male default is used as a convenience, there is no or very limited data about women’s needs and the impact of product designs and other factors on them.

What’s worse, lacking gender-disambiguated data, women who are seeking to design products with women’s needs in mind find themselves in a catch-22. Perez explains, “In a field where women are at a disadvantage specifically because they are women […] data will be particularly crucial for female entrepreneurs” (175). Yet such data simply does not exist.

Perez provides a multitude of examples of the male default not working well for women. In everything from city design to snow plow scheduled, the male standard disadvantages women. The gravest examples have dire significance. For example, there are significant differences in the physicality of men and women.