In most datasets, research studies, and product designs, the standard reference point is an average male body and male lifestyle. Women are treated as a deviation from this norm rather than as half the population. This is not a deliberate conspiracy — it is an unconscious habit that has calcified over centuries of male-dominated knowledge-making.

The problem starts with what Criado Perez calls the 'gender data gap': the routine failure to collect, analyse, or report data broken down by sex. When data is not disaggregated, male patterns are assumed to be universal. Women are then measured against a standard that was never designed for them.

This default shows up everywhere: in the temperature of offices, the grip size of power tools, the weight of protective equipment, and the timing of public services. None of these feel like 'gender issues', yet all of them systematically disadvantage women.