Humankind

North and South American Indians were originally from Asia and reached the New World from Russia via a land bridge; they resemble the mongoloids of Indonesia, Tibet and West Central Asia.

There are three language families:

• Indo-European: Russian, Hittite, Persian, French, Swedish, Hindi, Greek, German, Spanish, English, Finnish, Estonian, Hungarian (may be connected by a common parent language).
• Uralic
• Semitic/Hamitic. Separate groupings of languages of N & S Americans, and of Australian aborigines and Dravidians.

Relationship between bipedalism and the larger brain in hominids. Brain size depends on its cooling mechanism capacity. Bipedal stance presents least amount of body area to hottest sun at midday (quadrupeds present a larger area) thus first step in brain cooling. Present day homo sapiens brain is cooled by veins over the surface of the brain from front to back along midline down to neck. Efficient cooling then permitted development of larger brains

Average height of hunter/gatherers in Greece and Turkey at the end of the Ice Age was 5'10" for men and 5'6" for women due to varied diet, less risk of famine and less disease as not living in large, crowded groups. Everyone (except infants, the sick and the old) joined in search for food, which was shared out equally. With the adoption of agriculture height fell to 5'3" (men) and 5'1" (women) as women's health suffered due to poorer diet, more frequent pregnancies and use as labour.

Humans not biologically equipped to live in populations far beyond tribal level. But cities have compensations of stimulation and opportunity, and in effect splitting into 'tribes'. An integrated, independent group with a common purpose diminishes its efficiency as its size increases beyond 20-25 people. Voluntary social groups (family + friends) tend to have up to 100 members. Optimum cohesive size extends to some 500 people.

Risk taking was a way to show off strength and fitness as a mate; smoking, drugs and drink are risky behaviours but costs outweigh benefits. Adverts still promote risk taking images. Art requires skill to create and wealth/status to acquire, so is also a display of status.

Genocide is not new; motives are (1) land, (2) power struggle within a pluralistic society, (3) scapegoat killings of a helpless minority and (4) racial or religious persecutions.

Adultery laws, until recently, existed to secure a married man's confidence in the paternity of his children. Sexual jealousy is one of the commonest causes of homicide.

Choosing marriage partners: highest correlation (c.90%) is for religion, ethnic background, race, socio-economic status, age and political views. Next at 40% is personality (e.g. extroversion, neatness). Then 20% physical traits - all mostly subconscious (height, weight, eye and skin colour and down to features such as distance between eyes and lung volume). We tend to marry someone who resembles the parent of the opposite sex and learn subconsciously that imitimate associates from birth up to 6 years old are ineligible as sex partners later on.

Humans view people as 'us' or 'them' and rules about treatment of 'us' do not apply to 'them'. Generally there is a lack of response by outside parties to genocide but surviving victims describe the effecs as psychologically numbing. Today in many countries, people of different races, religions and ethnic groups live together with varying degrees of social justice but without mass murder - perhaps modern travel, television and photography help blur the 'them' and 'us' distinction. However the potential for genocide is still possible and the growth of world population may incite it.

Humans have in the past exterminated other species, mostly for food, sometimes by destroying habitat. Small, long-established egalitarian societies tend to evolve conservationist practices, but damage is likely to occur when (1) people suddenly colonise an unfamiliar environment, (2) people advance along a new frontier when they have damaged the region behind them, (3) people acquire a new technology whose destructive potential has not been evaluated, and (4) centralised states concentrate wealth in the hands of rulers who are out of touch with their environment.

Stan Gooch: Cities of Dreams.
Jared Diamond: The Rise and Fall of the Third Chimpanzee.
Terence Dixon and Martin Lucas: The Human Race.
Peter J. Wilson: Man: the Promising Primate.
BBC2 Horizon broadcast 14 March 1994