The limbic system is a mammalian innovation. It serves to mediate hormonal and psychological responses to intimacy. Like the brain stem, the limbic system has multiple structures, riding atop the brain stem, and covered by the cerebrum. These include the fornix, the thalamus, the hypothalamus, and the amygdala. These are arranged in partial layers, allowing denser and more complex interconnection between the components of the limbic system than between those of the brain stem.
The primary behavioral consequence of the limbic system is to create emotional context that motivates mammals to share resources. The emotions arising here are love (in the vernacular), compassion, and commitment. While there are a number of social advantages to this conditioning, it is a simple biological necessity to the survival of mammalian infants, which are incapable of caring for themselves for weeks, months, or years after their birth.
Every mammal also has a cerebrum that becomes progressively more sophisticated as we move up the evolutionary ladder. However, in the most reptilian of mammals, the cerebrum is barely more than a layer over the limbic system.
In the human species, it appears that feminine personalities have the stronger cerebral integration with the limbic system. This stands to reason: the bonding influence must be far stronger for the sex that must remain constant through nine months of parasitic invasion, and the subsequent years of dependency until the infant becomes a child.
Some authors indicate that this tendency is remarkably pronounced during the child-bearing years. Prepubescent and postmenopausal women manifest another personality type. Given the duration of the fertile phase, female thought processes are obviously deeply patterned by their limbic system. Menopausal women state that they feel as though the are "losing the minds". At some level, they are: as the limbic system ramps down, their ability to access established mental states - including memories - is degraded. They must re-establish new mental modes before they can resume a "normal" life.
As a society, we have come to celebrate the limbic Eden. I have male friends that have returned to their divorced wives, and adopted the practice of sleeping in the family bed: infant, man and wife all together. I experience this practice as a pleasurable haze, in which the sense of individual identity becomes lessened.
Clearly, in moral society, this can be advantageous. Emotions that motivate us to focus on the well-being of our intimates are civilizing. When we learn to employ them in other contexts, our conduct is less combative. It appears undeniable that "feminine" society is less destructive than "male" society.
When women congregate, they form a social web that is immensely powerful. They can develop an apprehension of wellness and continuity that smoothes over difficulties, and leads to immediate and effective response in times of crisis. Historically, this has been a feminine domain. I have encountered statements that women are the guardians of religious faith, that men only enter holiness in the arms of a woman, and that women prop up male spiritual leaders.