A philosophical principle is attributed to William von Ockham, a late English academic,

Main temple + Intihuatana, Machu Picchu, Peru
Main temple + Intihuatana, Machu Picchu, Peru

since the simplest explanation of a phenomenon is preferable to the more complicated ones. If one fact or argument is true and at the same time sufficient for an explanation, other explanations must be rejected.

In the case of the evolution of the human brain, this means: The biological explanation of the development of the human brain is based on true facts and offers a sufficient explanation. All more complicated explanations based on tool use, language, or other cultural achievements are to be rejected.

When comparing the development of the human body, including that of the brain, on the one hand and human culture on the other, the large gap in time between the appearance of Homo sapiens about 250,000 years ago and the first cultural artefacts with symbols about 60,000 years ago in South Africa needs to be considered.

This large gap in time is further evidence of the temporal disparity between previous biological and later intellectual and cultural development.


Hypothesis 12


Temple Square, Machu Picchu, Peru
Temple Square, Machu Picchu, Peru

The human brain was created on a purely biological basis without the influence of intellectual/cultural forces on the biological evolutionary process and even before the development of human culture.


The brain is a very expensive organ for the organism because it is energy-intensive and prefers to be supplied with energy. Growth up to the size of the human brain, and the end of that growth because of human reproductive biology, can be explained biologically.

This excludes more complicated mental or cultural causes according to the philosophical principle of Ockham’s razor.