[…] Swedish scientists have done extensive research on this and they found we first lived in small groups of 20 to 100 people who in any given week averaged 2.5 days for gathering and hunting and 4.5 days on talking. The conclusion they came to from this data was that the brain, the neurological system, and our hormonal systems have had 90,000 years of programming us for talk and collaboration, and only 10,000 years for competition and fighting. source …