Not intending to restate the obvious here:
- smaller height and weight
- smaller primary muscle groups
- socialization against violence
- helpless or weak "victim" mindset
- inappropiate dress for defense (short skirts, handbags, etc.)
For women, I would add even more:
proper choice of weapon
In general I don't recomment punching with the fist to any of my students (male or female). Although we learn this in our boxing, the chance of injury to the hand is higher than using the open hand or hammerfist to strike. For women, I suggest the fingernails when attacking soft targets like eyes or throat. Adding regular layers of nail strengthener can develop the claws' hardness to be very effective weapons. Kicking the low lines (especially foot stomp or low kick with heels) and CQB weapons like headbutt, elbows, and knees otherwise. While high heels can compromise the balance a bit, one of my former students in Chicago backkicked an assailant with her heel and it was as effective as stabbing with a knife.
proper choice of target
The most effective targets for women are eyes, throat, knees/feet and groin.
Of these, the groin needs some further explanation. Striking the groin, especially the proverbial "kick in the balls" is often touted as a one shot stop. This is hardly true.
It can work, yes, but needs to be spot on or it may only enrage the attacker. As a man, I can say that the fight goes up a few notches when someone aims for my balls. I get mad, and I want to completely destroy anyone who tries that on me and fails. This means it is a high risk, high reward strategy. If you miss, you have a much more serious fight on your hands. In addition, every man who has any experience at all knows to protect his groin. It is usually not an easily available target.
The best option for the groin is the grab. I suggest the palm heel hit, followed by grab, twist and pull. This has the highest chance of success and can work if attacker is in front or behind (bearhug or rear choke). Grabbing the groin causes a shock reaction in the mammalian part of the male brain that is more effective as a deterrent than a strike.
proper choice of technique
I resiterate here that simple is best. Eye jabs, throat hits, groin grabs, low line kicks to knees or top of the foot, knees/elbows/headbutts all have their place in women's self defense. Attacks which immobilize, such as low kicks or stomps, also can be effective since the goal is to escape the situation. I am not a huge fan of locks and grappling for women since most of the time they will lose on the ground, and proper locking under stress requires a lot of practice to be effective under pressure.
There are some choices for women, given that they often carry handbags or purses. It is important to consider that it is not easy to draw a weapon under pressure, so it is best to have something which can be carried innocuously (such as kubotan key chain, dulo dulo or the like). I am personally not a huge fan of pepper sprays or stun guns, since there are plenty of stories of violent offenders who shrug these off and complete their assault. The heavy key chain is a good option since they keys add weight to punches and can be used to slash. An umbrella can also work if it is a solid heavy metal one.
Likewise, a heavy metal travel mug or thermos can be effective, too. A solid pen
or the classy Montblanc version can work well, too.
I don't advocate carrying knives or karambits, although this is surely better than being killed/raped. Likewise, guns are a no-no in my books, despite their effectiveness in the hands of a trained and determined user.
Sadly, women are often targets of violent crime. Good training, good mindset, and an "equalizer" or two can help make sure you or your better half walks away safely.