You may have heard this term before, and wonder what it was and what it had to do with your success with women. If so, you've come at the right place because that's what I'll try to answer in this post.

What is vulnerability?

Vulnerability is the fact of showing yourself as you are.

In our daily lifes, many of us put on masks and filters that makes us behave differently than we would normally, mostly because we're afraid of being disliked for what we are. We want everybody to like us, so we try to please everyone and thus change the way we act depending on who we're interacting with.

Thus it's obviously easier to be disliked for something you aren't than for something you are (because it hurts), the downside is that nobody will like you for what you truely are neither.

Simply : vulnerability is the expression of your authenticity.

Thanks OP, but what it has to do with success with women?

Vulnerability displays a very attractive mix of both confidence and sincerity. Why? Because that's the both qualities that are necessary to, but also developped by, the act of being vulnerable. It takes guts to take the risk of being judged for who you are! That's courageous, and courage and confidence always come together. Furthermore, you can't be vulnerable unless you're sincere, since you cannot be attacked for what you are not.

Why is it so attractive? Because everbody crave for confidence and sincerity. We often aren't as confident as we appear to be, so when somebody really self-confident like us, it means he's also confident in his attraction towards us. That's stable and reassuring. And if he's confident about it, he must have good reasons : that's flattering as well. Besides, we tend to trust more confidence than... actual truth! Think about when you were certain of something, but someone was asserting the opposite so confidently and with so much energy that it made you doubt, and you ended up almost agreeing with him. Just to realize few days later that it was all bullshit, and you were right.

Let's take an exemple on what is being vulnerable and how it impacts relationships.

John likes Sarah. She's an attractive girl and John see her everyday in class. She's hot. She got boobs. John likes boobs. Ok, know what?

John has two choice. He can either try to go under the radar, and try to sit next to her as much as possible, follow her at every pauses, hear her complain about how the exam was too easy (let's not have received ideas) and how she her last boyfriend broke her hearth. Soon, John has become Sarah's gay bestfriend. But sooner or later, John decide it's enough : after all he has done for Sarah, she still didn't saw how kind and attentionate he is, and how much of a good boyfriend he would make! He opens his hearth and tell her he's in love with her. Sarah don't understand : why this nice guy suddenly fell in love with her? She thought he was gay. Moreover, she fell betrayed : that's why he was so kind and understanding? He just wanted to sleep with her! What a dick. Sarah ignores John for the rest of his life. John is so lonely and ashamed that he applies for the Human Mission to Mars, the NASA feels sorry for poor John and sent him indeed to Mars, where he dies, alone.

Now realize that for John it's not a decent a life plan : he cannot center his life around one woman, and if he gets rejected, burn it all to the ground.

John has another choice. He can assumes that he's not perfect, but well enough to get an attractive girl like Sarah. He realizes that besides becoming his best self, there is very little he can do to make Sarah more attracted. In fact, she probably has already made up her mind. John decides he will go to Sarah at the end of the class, when she's not surrounded by friends so she have no social pressure, and tell her he finds her attractive and that he'd love to know more about her. Sarah is impressed. This guy just walked up and tell her he liked her, while she could reject him at anytime! She finds the fact that he didn't try to hide his feelings nor his intentions very attractive, she's thankfull for his honesty and she decides to give him a try.

They set up a date for a few days later when it's convenient for both of them, exchange numbers and part ways, both feeling like their day has just been brighten.

Now Sarah could have rejected John, for multiple reasons : she wasn't into him, she has a boyfriend, she just broke up or fight with somebody, she was having a bad day... all those reasons having nothing to do with John.

And by acting showing his vulnerability, besides demonstrating very attractive qualities, John also was straightforward and polarizing, which made, Sarah rejecting him or not, both of them gaining huge amounts of time by immediatly settings things straight and clear.

Yes, you still need to challenge her. Yes, you still need to develop an attractive personnality. Not it won't work everytime. But what I wanna show in this post, is that you gain a lot of time as well way more solid results by showing who you are and not trying to hide anything.

You'll end up attracting what suits you, and way more effortlessly than if you were overthinking in terms of techniques or game.

Hope it helps!

TL;DR : Vulnerability is the expression of your authentic self. It's very attractive because it demonstrates confidence and honesty, besides being polarizating.

EDIT: Read Mark Manson's Models for more on vulnerability!