I find it amazing that most people are statistically neurologically “normal”: 95% of people concentrate their existence on a somewhat limited range of diversity in various aspects of behavior. A lot can go wrong, and note that here we are only talking about pregnancies that were actually carried to term and resulted in a new person, while a significant number of pregnancies are not even recognized because they occur due to selfaborts here , here and there there are variations that make the embryo unviable.
I better not speak too loudly, or prolife at any cost advocates will want to engage in the hospitalization of postcoital women, perhaps saving embryos from their automatic process of developmental quality control. Between this selferasure of what doesn't work and the selforganization of the brain that has survived such intrinsic “quality control,” a majority of reasonably “normal” individuals emerge plus a minority of neurodivergent individuals.
And since a lot can go wrong, divergences also differ in the reason for their divergence. Therefore, it is rare for a “type” of neurodivergence to be clearly linked to genetic variation. For example, consider the shank genes, which encode proteins that build synapses, connections between neurons. Less than one percent of neurodivergent people on the autism spectrum who already represent a tiny minority of the population have parts missing in this specific part of the genome, which is exactly the same in all normal people. In fact, there are several ways to be autistic.
However, if you cut out a piece of one of these Shank genes, the result, 100% of the time, is an animal mouse, rat, monkey or human that suffers from anxiety and whose social behavior is altered in several aspects.
And my colleagues in Portugal just added the poor Paulistinha fish to the list (sorry, fish lovers). This is it: Reproducing the genetic change associated with autism in a fish, even in a minority of autistic people, creates a fish that we just don't call autistic because everyone would roll their eyes, so we call it Just Mutant Fish To Schaft3a.
This is the work of Rui Oliveira's team from the Instituto Gulbenkian de Ciências and the Instituto Universitário de Portugal. When watching videos of other fish from a corridor (yes, fish pay attention to screens too), “normal” fish turn their body away from the other fish in the direction of the video of the fish, which shows erratic and disorganized swimming in response to an alarm in the other In the video he swims calmly but the mutants don't care and continue on their own, ignoring the others. Once the other person's stress is over, the normal fish continue to prefer to look where the stressed fish was and the mutants still don't care: they continue to look ahead in the corridor.
Conclusion: Genetically autistic fish are the only ones that follow the British recommendation “Stay Calm and Carry On”.
I ask Rui if they have any evidence that immunity to other people's stress is harmful to someone, the prerequisite for something to qualify as a “disorder.” Rui would like to answer this, but he can't: the necessary experiment would involve exposing his fish to predators, something the ethics committee didn't allow. But I imagine they had a good cod lunch right after…