Dialogue on pheromones: Avery Gilbert / James V. Kohl
December 12, 2010 | jim
I’ve edited and reproduced my comments here with an indicator of the point I was trying to address:
1. Some people may believe that the evidence for priming pheromones in mammals is weak and artifactual.
The required levels of biological organization (i.e., gene-cell-tissue-organ-organ system) have been detailed. So has the evolved neurophysiological mechanism that links mammalian pheromones to their priming effect on hormones. The evidence is not weak, it’s overwhelming!
2. Dr. Doty stretches the definition of pheromone to include or exclude his qualifiers.
I do not advocate stretching the original definition of pheromones. They are social odors and they release definite behaviors. The definite behaviors exist because of the developmental (hormone-driven) processes the pheromones effect.
3. Dr. Doty limits the definition of pheromone to include or exclude his qualifiers.
I do not advocate limiting the original definition. There is no science from any species that indicates that the concept infers (as Doty does on page 3) “…that a plurality of mammalian behaviors and endocrine responses is uniquely determined in an invariant way by single or small sets of chemical stimuli….”
4. Experiments with male mice show that application of Chanel No. 5 causes him to prefer to mate with Chanel No. 5 scented females. That makes Chanel No. 5 a pheromone.
The male mouse (or the males and females of any species) must first have been genetically predisposed to respond (or not) to the epigenetic influence (on hormones) of a mother’s pheromones. Otherwise no animal could be conditioned to respond to the initial association of a mother’s pheromones with the odor of a perfume.
5. General comments on alternative beliefs about sex pheromones, which include (A) no chemical qualifies as a human sex pheromone (B) many chemicals qualify as human pheromones (C) human sex pheromones do not exist.
Maternal pheromones can be considered sex pheromones because females produce more of the hormones that metabolize to the pheromones of females than do males (and vice versa). These sex pheromones also are processed by a sexually differentiated olfactory system, which allows them to have a different effect on the hormones of males than on the hormones of females, and the effect on hormones is what causes the behavioral affects.
The sexual dimorphism is the main reason to keep the concept of sex pheromones, as they are central to the development of sexual preferences. Food odors, for comparison, are central to the development of food preferences, but there is no sexual dimorphism in the food odors or in their effect on the hormones of males and females, or in how those hormones affect behavior.
If we eliminate the concept of sex pheromones, there is no biologically based explanation for the development of either typical or atypical mammalian sexual preferences (and associated behaviors that are sometimes manifest). Doty’s attempt to disprove the existence of mammalian pheromones, which include mammalian sex pheromones, is akin to me attempting to prove that food odors don’t exist. After all, no single or small sets of food odor uniquely determine in an invariant way the plurality of mammalian behaviors and endocrine responses associated with the development of food preferences.
The rest of the story will become much clearer in the next few months as the eusocial insect model of olfactory/pheromonal influences is extended to mammals, including humans.