Norm is a statistical term. Similar to average. Norms and averages exist to enable planners, advertisers etc to work out their target population. As such, they exist for a reason, but individuals hardly ever conform to them - eg, the average number of legs adult humans have is less than 2 because amputees exist. Average heights, or the norms for heights, can be calculated and can be useful for eg assessing population nutrition and health. But most people are not average height.
Stereotypes are different - something related to fashion and what can be sold to a target audience. Not real, not rooted in fact, just in fantasy.
Biological sex exists, and DSDs notwithstanding, it is a binary and there is no spectrum. The way human beings live, otoh, is infinitely variable.