There is a problem associated with the actual phase of brain development associated with sexual activity. Thus, several instincts are included in PSM, which are associated with sexual behaviour, too. These instincts will block for instance the tendencies towards homosexuality, incest and pedophily. The evolution of the brain to symbolic models results also in the reduction in importance of the instincts with negative consequences, at least in a transient phase. Thus, the speed of diminishing the importance of instincts is different from the speed of evolution towards symbolic models. The protection structure based on symbolic models would predict the long-term effects of a sexual decision. When a prediction shows a negative effect, the decision is to avoid such activities. This method should replace the method based on instincts situated in the PSM. At this point, we are in a relatively dangerous transient phase. The protection structure based on symbolic models is not implemented yet, while the protection system based on the instincts is less and less efficient. On very long range (i.e. over hundred years from now) the whole protection structure will be implemented based on symbolic models. This means that any sexual activity will be conditioned by the predictions on symbolic models. The normal sexual behaviour, in 100 years from now, will be very different from today. It is very likely that this prediction will be confirmed for the symbolic countries. For the 'image' countries, due to fundamentalism, one can assume that a fraction of the population, at least, will turn back to the protection system based on instincts. It is very difficult to evaluate the global effect of the mentioned behaviour on these countries. ETA 33: The internal body MDT is associated with the main brain which, among other functions, controls also the external body (hands, legs, etc). For the internal body (internal organs...), there is an extra brain, which is a technological process brain. This process brain contains basically an image model of the whole internal body (its external reality contains the whole internal body). Its scope is to maintain the stability of the whole internal body. When a perturbation occurs, a model will simulate one or several solutions, in order to regain the equilibrium. There is a connection between the main brain and the process brain, as it can be seen experimentally. Thus, a bad psychological state (many unfavourable predictions) can produce perturbations in the functions of the internal organs. The inverse influence also exists: a healthy psychological structure can improve the general health. Situations exist when several perturbations appear among the systems of the internal body. In a complex situation, the model cannot understand anymore what happened, due to the too complex structure. Some nonconventional medical treaments exist, which can be used to control such situations.