Two hypotheses are presented as frameworks for human evolution. The General Intelligence Hypothesis is based on empiric research of intelligence and confirms that Homo is more intelligent than Pan. Homo is a fast learner. The assumption in the GIH is that somewhere in the human evolutionary process there have been circumstances and environmental chances that acquired more sense and apprehension, more consciousness, to survive. There are many ideas about potential environmental chances in the Homo evolution and their effect on the growth of consciousness. The Sexual and Social Intelligence Hypothesis states that fast learning in Homo derived from necessary sexual skills as a consequence of having sex by making love. Making love demands psychological and cognitive skills like empathy and emotional reflection, estimating intentionality of the potential mate and -of importance- physical/manual skills too. The assumption in the SSIH is that making love -and being repeatedly selected as a mate- gave rise to judging and being judged. This phenomenon of sexual judging -based on the experienced orgasm- let to natural selection on self reflection and on (self)consciousness of ones own acts and sexual accomplishments. The difference between the General Intelligence Hypothesis and the SSIH is that the latter presumes fast learning to have emerged inside out. To have sex, make love, it is worth learning sexual skills. Having sex has many positive effects on body and brain (neurotransmitters). And of course having sex is essential for vertical evolution and offspring (genetic transmission). The Sexual and Social Intelligence Hypothesis supposes that learning sexual skills is at the base of the expanding general human intelligence regardless of the circumstances 5-6 million years ago.
A second hypothesis is called the Social and Cultural Intelligence Hypothesis. SCIH relates evolutionary acquired human intelligence to increasing social complexity. In the Sexual and Social Intelligence Hypothesis making love -Homo- has made having sex more and more complicated. On the one hand because of required psychological, emotional and manual skills. On the other hand because making love is, as opposed to straightforward penetration, a process in time with many variables and with emotional and manual adjustments during the process. Besides one never knows -estimating intentionality and preferences- on which selection criteria individuals choose their mating partners; will it be me?
In the Sexual and Social Intelligence Hypothesis every individual is part of the social world (mate selection) and thereby of the surroundings and the environment. From a biosemiotic perspective; the potential mate belongs to the Umwelt. He/she can and has to be signified as a preferred sexual partner. The preferred sexual mate at the same time is (emotio-sexual) represented in the brain and part of the individuals inner world. In biosemiotic terms sexual partners belong to both endoseimiosis and exoseimiosis. Neuroscientific research agrees on the fact that the function of the human neocortex is to absorb, signify and represent social and sexual interactions (first and second order) and intentions. And making love has of course many cultural aspects. It can be learned by watching and imitating.
The fact of the matter is how to define intelligence. Not until intelligence is unravelled in its many components can we compose a broad-based hypothesis on the evolution of human intelligence. The Sexual and Social Intelligence Hypothesis assumes intelligence to contain many psychological, physical, neurological, biochemical and biosemiotic elements, including genetic and neurobiological tools and evolutionary (sexual) acquired skills.