Dunbar's number

The Dunbar's number is, according to the anthropologist Robin Dunbar, the theoretical cognitive number of individuals that can develop fully in a given system. He theorizes that this value (of approximately 150 individuals), its related to the size of the brain neocortex, and his processing capacity.

The primatologists noted that because of their highly sociable nature the non-human primates have to maintain personal contact with the other members of his social group. The number of members with who a primate can maintain said contact seems to be restricted by the size of the neocortex, and that suggests that there is an index of group size relative to the specie. So in 1992 Dunbar used the correlation observed in primates to predict the size of the social group in humans. He predicted a size of 147.8 group members, usually represented as 150.

Dunbar compared this prediction with observable human groups and noted that the groups fall in three categories, of 30-50, 100-200, and 500-2500.The research of Dunbar on the size of tribes and villages seemed to corroborate his prediction: 150 was the estimated size of a village farmer of the Neolithic; 150, as the point of break and separation of a hutterite settlement and 150 as the basic size of a military unit in ancient Rome and in modern times since the 16th century.Dunbar theorized that a group with a size of 150 persons needs to have a very high incentive to stay together, thus 150 members groups only occur due to an absolute necessity, for example, aggressive economic pressure. For a group this size to maintain such cohesion, he speculated was needed to dedicate a 42% of the time to socialization; a dispersed group would have fewer ties, meeting less frequently.

Dunbar proposed also that the language may have generated as an easy way to socialize, because without language the humans would have had to occupy almost half their time socializing; the language may have allowed societies to remain cohesive, reducing the need for physical and social intimacy.

It's considered that -according to Dunbar's theory- in small-scale (less tan 150 individuals) most social orders could function properly, but due to population growth, problems arise due to the difficulty of maintaining properly controlled relations between individuals. This theory also applies to problems of overpopulation, because the further away a group moves of the hypothetical limit of 150 in any delimited system, its more likely for conflict to grow.

Pandora's box

In greek mythology, Pandora (Πανδώρα) was the first woman, made by order of Zeus to introduce evil in human life after the titan Prometheus stole the fire that the sun god carried on his chariot and gave it to the humans.

The first two appearances of Pandora in Greek literature occur in "Theogony" and "Works and Days" both works of Hesiod. When mortals and Immortals separated, Prometheus hatched a deceit so that in the future, in the making of sacrifices to the gods, they could keep the meat and viscera for themselves. Zeus, angered by the scheme, denied fire to men, but Prometheus stole it for them.

Zeus ordered Hephaestus to model a clay image with the figure of a lovely maiden, similar in beauty to the immortal, and to give life to her. But while he sent Aphrodite to give her grace and sensuality and Athena along with the Graces and the Hours to give her domain of the arts related to the loom and garnish, Hermes job was to sow lies, seduction and a voluble character in her. This all in order to set up a "beautiful evil", a gift that men are glad to receive, actually accepting countless misfortunes. Then Zeus sent her to the home of Prometheus and his brother Epimetheus, who despite having been warned of the impending vengeance of Zeus accepted his gift and married her.

Hesiod states that mankind have lived free of fatigue and disease, but Pandora opened a jar that contained all the evils (the expression "Pandora's box" is a deformation Renaissance) releasing all human misfortunes. The amphora was closed just before that hope was liberated.

There are other versions of the myth which tell the jar contained goods and not evils. The opening of the jar caused the goods to fly back to the mansions of the gods, removing themselves from the life of men, who live on only afflicted by evil... and who could only keep hope.