- Humans lost hair at around the same time they left the trees: around 3 million years ago. Evidence of this is in fossilised, separate pubic and hair lice, on homo erectus.
- Only 3% of mammal species are monogamous, and monkeys and apes are often polygamous, but humans are monogamous (perhaps) because it stopped men from killing other people's children (birthed by "his wife", which, in polygamy, is shared by others). "Of the 1,231 societies listed in the 1980 Ethnographic Atlas, 186 were found to be monogamous; 453 had occasional polygyny; 588 had more frequent polygyny; and 4 had polyandry."
- Illiterate people cannot read or write. They can still speak.
- The difference between dementia and normal aging is what you forget; it is normal to forget what you did last year, but not if you forget what you just ate for breakfast.
- Concentrated sulphuric acid is harmful to the body (nsfw).
- Humans may have domesticated themselves by either killing, or refusing to mate, with violent males.
- The probability of you having at least one friend of another race is dependent on your country's demographics. In America, while 75% of whites have only white friends (because whites are the largest demographic), blacks with blacks is only 65% (because they are the second largest demographic), and half of the hispanics have trouble keeping their friendships exclusively hispanic.
- Individualistic aka "Me" societies, which include the US and western Europe, believe each individual is responsible for their own well-being (and, to a certain extent, for their immediate family members). Collectivist aka "We" societies, which include China, India, and Japan, think each individual is responsible for their group.
- Democracy as a concept appeared in the form of "consensus" in early human history. The kind that is frequently brought up is Greek, Athenian democracy, which, although not the first in any way, was one of the example democracies with sufficient historical records to back up the fact that it did have one. At first, it consisted of just this: it gave the right of every Athenian man the right to participate in assembly meetings.