“Male love circuits get an extra kick when stress levels are high. After an intense physical challenge, for instance, males will bond quickly and sexually with the first willing female they lay eyes on.Women, by contrast, will rebuff advances or expressions of affection and desire when under stress. The reason may be that the stress hormone cortisol blocks oxytocin's action in the female brain, abruptly shutting off a woman's desire for sex and physical touch.”

“During times of physical separation, when touching and caressing is impossible, a deep, longing, almost a hunger, for the beloved can set in. We are used to thinking of this longing as only psychological, but it's actually physical. The brain is virtually in a drug-withdrawal state. During a separation, motivation for reunion can reach a fever pitch in the brain. Activities such as caressing, kissing, gazing, hugging, and orgasm can replenish the chemical bond of love and trust in the brain. The oxytocin-dopamine rush once again suppresses anxiety and skepticism and reinforces the love circuits in the brain. From an experiment we also know that oxytocin is naturally released in the brain after a twenty-second hug from a partner- sealing the bond between huggers and triggering the brain's trust circuits.”

“Women have less direct relationship to anger...When a woman "bites" her tongue to avoid expressing anger, its not at all socialization. A lot of it is brain circuitry. Even if a woman wanted to express her anger right away, often her brain circuits would attempt to hijack this response, to reflect on it first out of fear and anticipation of retaliation. Also, the female brain has a tremendous aversion to conflict, which is set up by fear of angering the other person and losing the relationship. Instead of triggering a quick action response in the brain, as it does in males, anger in girls and women moves through the brain's gut feeling, conflict-pain anticipation, and verbal circuits. Scientists speculate that though a woman is slower to act out of anger, once her faster verbal circuits get going, they can cause her to unleash a barrage of angry words that a man cant match.Typical men speak fewer words and have less verbal fluency than women, so they may be handicapped in angry exchanges with women. Often when I see a couple who are not communicating well, the problem I see is that the man's brain's circuits push him frequently and quickly to an angry, aggressive reaction, and the woman feels frightened and shuts down.”

“Female sexual turn on begins, ironically, with a brain turn off. The impulses can rush to the pleasure centers and trigger orgasm only if the amygdala- the fear and anxiety center of the brain- has been deactivated. The fact that a woman requires this extra neurological step may account for why it takes her on average three to ten times longer than the typical man to reach orgasm.”

“Darwin theorized that mankind (both male and female) evolved alongside each other over millions of years, both reproducing after their own kind before the ability to physically have sex evolved. They did this through “asexuality” (“without sexual desire or activity or lacking any apparent sex or sex organs”). Each of them split in half: “Asexual organisms reproduce by fission (splitting in half).”

“(In actuality there are no such things as "male" or "female" hormones. Hormones have no sex of their own, and all types of sex hormones are present in all human beings in varying amounts.)”

“How does stress influence the midbrain pleasure circuit (or the feeding control circuits)? The short answer is that we don't really know. However, there are some tantalizing initial clues. Recall that twenty-four hours after a single exposure to cocaine, the excitatory glutamate-using synapses recived by VTA dopamine neurons express LTP. This change, which will result in greater dopamine release in VTA target areas, could also be produced by nicotine, mophine, amphetamines, or alcohol. Amazingly, even breif exposure to stress (a rat's five-minute-long forced swim in cold water) also produced LTP of the VTA synapses that was indistinguishable from that evoked by drugs. What's more, the stress-induced LTP could be prevented by pretreatment with a corticosterone receptor blocker. This suggests that drugs and stress rewire the pleasure circuit in overlapping ways and that the stress response to trigger LTP in the VTA requires a stress hormone signaling loop from the brain to the body and back.”