Even with today’s contraceptive options, more than a third of pregnancies are unintended. How would the world change if women only ever got pregnant when, and at the age, they wanted?

Of the nearly 90 women who turned up for pre-selection, 37 progressed to the three-day try out. Modelled after special forces selection, the women were challenged with various endurance and team building trials, such as packing up a 200-pound (90kg) tent, dragging it up a mountain with their legs tied together, and then reassembling it. Only three women dropped out – an astonishing rate, considering that the majority of male ranger recruits typically quit in the first days of try-outs.

While there is an ongoing debate about the extent to which nature versus nurture influences things like dominance and aggressiveness, it's not impossible that suddenly-stronger women would experience at least some enhancement of these traditionally male traits. Additionally, self-entitlement, proneness to anger and bargaining confidence in women tend to be linked to physical attractiveness, so strength may simply replace looks as the impetus behind those personality traits.