Animal cognition (reasoning) in the light of genetic ideas

Abstract

The historical overview is presented of genetic experiments in L.V. Krushinsky’s laboratory in Moscow State University. L.V. Krushinsky stated the three-component concept of animal behavior. He claimed that animal behavior has not only innate species specific behavior and the learning ability, but should be supplemented by another mental category, reasoning the ability for elementary logic operarions. Being rather lonesome at the beginning, Krushinsky got the spiritual support from D.K. Belyaev and B.L. Astaurov. The attempt to study the genetic bases of reasoning ability was performed in Krushinsky’s lab using the trait “extrapolation problem solving”, which meant the ability of an unexperienced naïve animal to find the food bait when it moved aside and disappeared from (not “in”) the view. The selection for high scores of this trait in the hybrid rat population (Norway rat × laboratory strain cross) was started. Initially the hybrid rats solved this problem in the statistically significant proportions, while the animals from further selection generations demonstrated the dramatic increase of anxiety (in spite of extensive handling of these animals), which made further experiments impossible. Much later another selection experiment started in which mice of a genetically heterogeneous population were selected for high scores of extrapolation problem and concomitantly for the lack-ofanxiety signs during the testing procedure. This selection for a cognitive trait produced some positive results, although the direct response to selection was very weak. The data obtained show the intricate connection between the mouse ability to solve the problem and the processes of anxiety, which in turn looks as non-uniform by its nature and mechanisms. The data from experiments performed in classical genetics should be combined with the new knowledge concerning the role of single genes determining animal behavior.

Keywords

• animal behavior
• cognitive tests
• selection
• anxiety
• rats
• mice.