Some people think that certain aspects of human behavior are difficult or impossible to model in other animals. To me, this indicates what’s wrong with behavioral science. Is it science if we can’t infer anything about causality from other species? Clearly, the molecular biology of all species is the same. Why not use molecular biology as the basis for the examination of behavior across species?
An ontogenetic and phylogenetic perspective shows that principles of biology and levels of biological organization constrain the link between sensory input and behavior. The link must involve one or more steps in a gene-cell-tissue-organ-organ system pathway that links sensory input to behavior. For example, single-celled organisms have genes in cells (i.e., two steps of a five-step pathway in mammals) but they do not exhibit any complex system-driven behavior. Compared to mammals, single-celled organisms lack the required tissue in the organs of an organ system like the mammalian central nervous system (CNS).
The mammalian CNS can only allow for biologically constrained behaviors. But, with the evolutionary advent of tissue in organs of the organ system that directs brain-based behavior (i.e., the CNS), behavior is less constrained. Thus, evolutionary biology allows for more diverse behaviors across species.
Language, culture and “free will” do not exist outside biological constraints. This suggests that even the complex mind of a human being can be modeled within the biological constraints of the brain. We may not yet know enough to completely detail an animal model of the mind, but we have certainly made some progress towards modeling “the mind’s eyes.” That progress came with the understanding that visual input cannot be directly linked to behavior via a gene-cell-tissue-organ-organ system pathway in any animal.
We owe a lot of the perceived mind-brain dualism to thoughts about what drives our behavior, but what we think does not matter. What we see does not drive our behavior, and neither does what we say or hear. Tactile sensation may activate reflexes, but reflexes are not brain-based behavior. Instead, the chemical senses drive the behavior of all species, and the molecular mechanisms that allow this are modeled in other species – all of them.
Food odors drive behaviors associated with food acquisition; social odors drive behaviors associated with mate acquisition. Responses to food and to potential mates are conditioned to occur in the presence of other sensory input, like what we see or hear. But visual and auditory input is not required as part of the biology of behavior.
Odors activate genes in cells of tissue in the mammalian brain, and odors drive the behavior of all species.
Juvenile play conditions sexual partner preference in adult female rats Original Research Article
Physiology & Behavior, In Press, Accepted Manuscript, Available online 14 July 2011
Pedro Paredes-Ramos, Marta Miquel, Jorge Manzo, Genaro A. Coria-Avila
► Neutral odors paired with juvenile play induce an olfactory conditioned play partner preference in prepubescent female rats ► The same conditioned odors (CS+) induce conditioned sexual partner preference in adult female rats. ► Sexual partner preference is observed with more proceptive behaviors directed towards the CS + male, which responds with more mounts, intromissions and ejaculations. ► This conditioned preference may be strong enough to support assortative mating.