Sexual selection and human evolution

The Sexual and Social Intelligence Hypothesis (SSIH) offers a search direction to evolutionary questions as: ‘How did humans develop curiosity about their environment? How did human signification emerge? How did humans gain a specific form of consciousness compared to other highly intelligent primates?’

In ‘Skilled lovers; on the evolution of sex, cognition and curiosity’ a line of inquiry is outlined for the evolutionary separation of Pan and Homo. Pan is the closest (living) relative of Homo; we know them as chimpanzees and bonobo’s. It is generally accepted that Pan en Homo divided some 5-6 million years ago. This means that Pan and Homo had a common ancestor. The Sexual and Social Intelligence Hypothesis maps biological and psychological similarities between (current) Pan en Homo to pinpoint a -till now- scientifically unknown common ancestor. The explanation framework of SSIH is based on biosemiotics (natural science) and on affective neuroscience (humanities). Biosemiotics is about representations in the brain, signification and awareness. Affective neuroscience is about emotional behaviour patterns, focus of attention and readiness to act.

In short the Sexual and Social Intelligence Hypothesis uses an evolutionary biological axiom called sexual selection to explain the origin of two species, Pan and Homo. From a biological -anatomical- perspective female sex organs in (current) Pan and Homo are very distinctive. In (current) Homo female sex organs are differentiated in reproductive organs like uterus and ovary on the one hand and in sexual organs like corpus cavernosum and clitoris on the other hand. This distinction is far more explicit in Homo than in the female sex organs of Pan. Sexual organs are physically and physiologically joined with spinal cord and cerebrospinal fluid, whereas reproductive organs are related to the blood circulation. These physiological and anatomical facts must be subject of scientific research. Because changes in distinctions between sex and reproductive organs assume many underlying biological and genetic mutations in human evolution. In fact from a biological evolutionary perspective the blood-brain barrier has changed. The anatomy of the pelvis has changed (walking on two legs?). And most of all in Homo the possibility arised to distinguish sexual behaviour from reproductive behaviour.

In the Sexual and Social Intelligence Hypothesis the differentiation between sexual and reproductive behaviour is key factor underneath the human evolution along sexual selection. A new axiom introduced in the academic field of evolutionary biology is that (female) orgasm was crucial for separating Pan and Homo over million of years. It is the (female) orgasm that bridges the gap between feeling, thinking and selecting a sexual partner (biosemiotics and neuropsychology), and between genetics and evolutionary phenomenology (species and ethology).