Spiders, snakes : where do the phobias animal ?

Indiana Jones and the face of the perspetive of natural selection

Published the 22.10.2017 at 19: 33

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phobieserpentaraignéearachnophobiepsychologieévolution

Who remembers the pit of snakes in Indiana Jones ? All the world, and for good reason : the phobia of snakes are among the most prevalent. About 1 to 5 % of the population is subject, and more than a third of us feel at least a form of aversion. It’s the same for most of the phobias of animals, which belong to the field of specific phobias (as opposed to social phobias, to more complex).

What causes these phobias ? Several approaches exist to explain them. Focusing on the case of little Hans, Freud had imagined that his terror of the horses was a result of the discharge of a fear of castration, the unconscious. Suffice to say that this point of view does not have the wind in its sails today. The pope of the behaviorist, Watson, was illustrated in the years 20 by conditioning little Albert, 1 year, to be afraid of rats. Two theories which lean towards the acquis.

Children first

Nowadays, it is the evolutionary perspective that holds the rope to the phobias animal. With a constant : again, we love the children… The experience of the day, initiated by the famous Max Planck Institute in Leipzig, has been conducted with babies who were asking for may be not so much. The researchers showed colored pictures which glided sometimes an intruder : fish – fish – snake ! – fish… Same as with flowers in a corolla, occasionally infiltrated by a large spider hairy.

Of course, the small guinea pigs, aged six months, on average, had not the leisure to run away. To detect for sure any reactions from bashful fright, the researchers observed the eyes of the children. These, unlike those, don’t lie : under the effect of the stress, and the discharge of norepinephrine that follows, the pupils tend to dilate by reflex.

Fear is the path

Fortunately, it turned out that the babies were fine eyes in the face of all these intruders scales and abdomens. “We conclude that fear of snakes and spiders is evolutionary origin “, welcomes Stefanie Hoehl, first author of the study. “As in other primates, there are brain mechanisms that are intended to identify such stimuli and to react extremely quickly. “

Specific phobias result, therefore, a genetic predisposition printed by natural selection. A mechanism strongly ” wired “, which would explain the significant prevalence of phobias of animals. After fifty million years to the mix of critters venomous, such as snakes and spiders, humanity will eventually learn collectively from mistakes. For once.