There are three MAJOR conflicts in women's lives, that are so intense, they force women to choose a dominant strategy, and that becomes part of her personality - which dictates significant behavioral differences - and determines which triggers makes her feel attracted, which behaviors make her feel comfortable, and what gets her turned on.
These three conflicts are: Time, Sex, and Relationship.
Conflict of Time - Women are biologically programmed to mate with the most dominant, high status man they can find so therefore she wants to spend time really screening the men she dates and finding the best one - but there is pressure from society to be with a guy who has high status - and it is looked down upon if a girl is single for a long time.
This is why you will see women who are older, becoming cougars, and becoming much more aggressive in dating, going out, and meeting guys. Even to the point of hitting on the guys instead as opposed to younger girls who are more likely to just sit there and let men approach them. It all has to do with her feeling that her time is running out...
With men - they actually get BETTER with age, more successful, better traveled, they have more sexual experience. And they can have children, now especially with Viagra, well into their 70's or 80's.
Conflict of Sex - She wants to enjoy the physical pleasure and emotional intimacy of sex - but sex in the past has led to emotional trauma and critical judgment from society and her peers.
This is why women will seem VERY into you, make out with you, let you touch her, but there's often an additional level of resistance right before you start having actual sex. We know it feels great for her, and often we don't understand her hesitation, but she's got an internal conflict preventing her from going all the way.
And men - we don't try to have sex with a girl, and then suddenly change our mind because we're scared of being judged. If anything our friends think we're even cooler for having more sex.
Conflict of Relationship - Her biological wiring drives her to support and nurture family, and develop her feminine self / but our male dominated society encourages achievement, status climbing and developing her career, just in case she doesn't find a man to provide for her.
This is why you'll see very successful women quitting their jobs or taking an extended leave when they have kids. For example, recently Nicole Kidman took a break from Hollywood to focus on raising her children. You won't see a man really taking a break from work to focus on his family - if anything he'll work even HARDER when he has more mouths to feed.