In Sanskrit the word char means to move or walk. Chaar means walking about or gait and achaar means behavior. Achaarya is one who teaches behavior and chaaritra means nature or conduct. Character has the same derivation and comes from the Greek kharakter meaning distinctive nature. It also means an instrument for marking or impressing.
In the Bhartruhari Shatak, there is a shloka (stanza) which lists the desires of human beings in temporal order starting with curiosity for knowledge, then in order, sex, money, power, fame and salvation (gnyaan, kaama, vitta, sattaa, kirti, moksha). Only salvation lacks a clear evolutionary or genetic basis and as I have emphasized many times in my earlier writings, is a complex product of fear, ignorance, ego, inability to accept mortality and a craving for justice denied in this life. It leads to a belief in god, afterlife and just reward or punishment to compensate for impotency in the only life that all living beings have.
This is not to promote a Hobbesian hell of uncontrolled selfish behavior with total disregard for others. Homo Sapiens could not have survived in the African Savannah (site of origin), except by forming bands and bonds. This is why we are all to some extent xenophobic as Shilpa Shetty realized to her chagrin on the road to money and fame. Predators like lions and other cats were too strong for our species to survive singly like the orangutans. We had abandoned arboreal existence and had become bipedal with erect posture, freeing the hands for prehensile activity and fine manipulation. Our feet unlike the monkeys lost their grasping ability. Erect posture required a change in pelvic bones, tilt and morphology, with migration anteriorly (forward) of the female vagina, making it more convenient for face to face copulation. This unique adaptation is what has led to the female breast fixation in human males. Chimpanzee and bonobo males pay no attention to their females' breasts during sex, even though bonobos mate face to face.
They also mate promiscuously without forming pair bonds. This creates uncertainty about who is the father and a generally benign behavior to nearly all young. They can do this because the mother is the primary care giver with little paternal investment. Baby apes can cling to the mother and pregnant ape females can easily take to the trees to escape predators. Pregnant human females would be seriously handicapped in evading predators and need a sheltered existence, at least in the third trimester. Thus a male or female of the group would have to provide for a pregnant human female. A newborn human is utterly helpless and remains so for much of childhood. This is because evolution pushed back human infant birth earlier to avoid the cephalo-pelvic disproportion of a smaller pelvic outlet due to erect posture, and the larger fully developed head. The baby's head grows substantially and reasonably after birth. The helpless baby and mother need the father's effort and care. It led to pair bonding and jealousy and no need for enlargement and reddening of the female vulva during estrus as seen in the apes. Thus ovulation was hidden or latent without advertisement. Remember that at that time humans were living naked as well. No male likes to be cuckolded by his wife and raise the baby of another male. This led to male monitoring and control of female sexual behavior, visible even today all over and more severe in orthodox Islam, and also greater abuse of stepchildren.
Group existence required the ability to identify members and distinguish strangers. The sense of smell was fading and we relied more on vision, so our modular brain reduced the rhinocortex (smell brain) and enlarged the visual cortex and the memory grid. A special area developed just to recognize faces. Group living requires the ability to critically evaluate the reliability of others in the group and to project one's own reliability. A module developed to detect cheaters and to exaggerate one's own goodness. The ability to read others minds and deceive them became important for survival, leading to a rapid growth of the human prefrontal cortex which allowed us to think strategically and make tools (axes, bows, arrows, ropes, metal swords and implements; agriculture, domesticate animals; war; understand the universe; rule the earth and hopefully not destroy it by global warming or nuclear war). It is this tendency to live in groups that is responsible for diverse languages and nations, and wars amongst tribes and nations. Religion, race and language are the divisive forces and money, sex and power the motivations for conflicts.
The unique trait of humans is language. This evolutionary faculty is best functional from age to twelve. This is why it is so difficult to learn new languages as an adult and why adults acquiring a language never get the native accent. It was Noam Chomsky who first proposed that we have a brain module for language acquisition. Children learn languages before being formally taught grammar and second languages learnt in school like Sanskrit, Greek, Latin, French, German, Spanish etc. are easily forgotten. The CIA language school uses immersion techniques. Speaking a language day to day is the best way to master it. There is a brain module for language which when damaged in adults by strokes or head injury leads to various forms of aphasia. A child acquires new vocabulary at the rate of a few words a day and most adults have vocabularies of tens of thousands of words. The environment decides what language the child learns. As many immigrant Indians know our children speak Indian languages with Indian accents and English with American accents even though the parents speak in heavily Indian accented English.
At adolescence, the teenager hormones act up and often lead to irresponsible behavior. Before that children associate with same sex peers and after that they have an attraction to the opposite sex, sometimes even detrimental or fatal. The hypothalamus in the brain is the modulator for it. To make breeding attractive, the brain has evolved to make sex tremendously pleasurable, even making two dimensional pictures arousing. Hence, the birth of pornography, female exploitation and trafficking. Imagine the old days when we had to live in caves and the only water was a nearby stream infested by predators. There were no diapers or baby formula. Pregnancy and motherhood were and are still not without risk. Even today in Afghanistan and Sub-Saharan Africa child and maternal mortality are very high. Males were attracted to hourglass figure females. Big breasts meant better ability to feed the baby and big hips meant easier birth passage for the newborn. Attractive face meant hope of a good looking baby. The female wanted a reliable and good provider. Even today men choose mates for looks and females for money or status. This explains rich and powerful males divorcing their old wives to obtain young trophy wives. Men do marry rich older wives for money like Demi Moore's young other and the prophet marrying Khadija. But no sooner Mohammed's wife died, he went on a shopping spree for young wives, including Ayesha aged nine.
After knowledge and wealth, human desire turns to power. When the American landowners and merchants attained that status, they fomented a rebellion against Britain, even though they were mainly of British origin. The tea tax was just an excuse, as Britain was very lenient in taxing America (read Iron Tears). After thirty years of independence the US started flexing its muscles by proposing the Monroe Doctrine to proclaim its sole right over the entire Western Hemisphere. This has now extended to the entire planet including space. Our current president who never got a proper education and made his money by his father's connections decided to run first for Governor of Texas and then the presidency, to the ruin of the nation. Having attained the power, he persists in the folly of prolonging the war in Iraq and extending it to Iran for his next desire of fame. He does not want defeat as his legacy so he will prolong the war and leave the mess to his successor. He will not get fame but wants to avoid infamy.
Finally, extreme religiosity has been associated with lesions in the temporal lobe of the brain. Temporal lobe epilepsy leads to out of body experiences like de ja vu, ja me vu, fugue states and other stereotypical strange behavior. It does not mean that all religious persons have a brain disease, unless and until one wants to list poor thinking and reasoning ability as a brain disease. Interested readers may wish to read Richard Dawkins' book 'The God Delusion' and Judith Harris' book 'No Two Alike', to diagnose the presidential malady.