The Common Neural Bases Between Sexual Desire and Love: A Multilevel Kernel Density fMRI Analysis by Cacioppo S, Bianchi-Demicheli F, Frum C, Pfaus JG, and Lewis JW Journal of Sexual Medicine 2012.
Given what appears to be previous work with JT Cacioppo, this work by S. Cacioppo et al., may be the clearest indication to date that love is a receptor-mediated event. If so, it’s attribution to humans is consistent with what is known about the requirement for gene activation by sensory input directly linked to neuroendocrine responses that have their origins in the evolution of the hypothalamus. That would help explain why love is difficult to quantify, and only somewhat easier to image. It might also explain brain imagery linked to sexual orientation.
Love and sexual desire are aspects of human behavior that seem most likely to be based on a lifetime of receptor-mediated events linked to genetic predispositions and sensory input from our environment. This links them to behaviors of non-human animals. Two decades of increasing focus on genes, steroid hormones, and visually perceived physical features seems to have clouded perspectives on epigenetic influences and receptor-mediated events that begin with ligand-receptor binding and the effects of GnRH pulsatility on other hormones that affect behavior.
Epigenetic effects of pheromones: A chronology
1991; A seminal work detailed the most likely role of gonadotropin releasing hormone (GnRH) in human sexual behavior. (Moss, Dudley, & Riskind, 1991).
1995; The role of pheromones across species and in human behavior was suggested in a book for a general audience (Kohl & Francoeur, 1995; 2002).
1996; The interactions among pheromones, molecular epigenetics, and GnRH during the development of adult sexual behavior was modeled (Diamond, Binstock, & Kohl, 1996).
2001; The unconscious affect of pheromones on GnRH on the development of heterosexual preferences in mammals was described (Kohl, Atzmueller, Fink, & Grammer, 2001).
2005; The effect of pheromones on GnRH was linked directly to control of sexual behavior (Boehm, Zou, & Buck, 2005).
2007; The evolution of the neurophysiological mechanisms in mammals that allow the receptor-mediated effect of pheromones on GnRH to control the development of homosexual male preferences in humans was described (Kohl, 2007).
2012; The molecular biology of how nutrient chemicals calibrate the survival of individuals and how the metabolism of nutrients to pheromones that standardizes and controls species survival appears to link the nature and nurture of receptor-mediated behavioral development across species (Kohl, in press).
Comments: Two decades of scientific progress since GnRH was first linked to human sexual behavior have failed to convince some researchers of what should have long ago become known and accepted. Namely, that nutrient chemicals and pheromones are directly responsible for the evolved behaviors of all species. Those who profess that other sensory input from the environment is more important to behavioral development should be asked for scientific evidence that supports their opinions about the basic principles of biology and levels of biological organization required to link cause and effect. When no support is found for their concept of how behavior develops, these professors should be asked to learn about the molecular biology of behavior that is common to all species. It is molecular biology that links nutrient chemicals and pheromones to behavior in species from microbes to man.
Bibliography
Boehm, U., Zou, Z., & Buck, L. B. (2005). Feedback loops link odor and pheromone signaling with reproduction. Cell, 123(4), 683-695.
Diamond, M., Binstock, T., & Kohl, J. V. (1996). From fertilization to adult sexual behavior. Horm Behav, 30(4), 333-353.
Kohl, J. V. (2007). The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences. In M. R. Kauth (Ed.), Handbook of the Evolution of Human Sexuality (pp. 313-369). Binghamton: Haworth Press.
Kohl, J. V. (in press). Human pheromones and food odors: Epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology.
Kohl, J. V., Atzmueller, M., Fink, B., & Grammer, K. (2001). Human pheromones: integrating neuroendocrinology and ethology. Neuro Endocrinol Lett, 22(5), 309-321.
Kohl, J. V., & Francoeur, R. T. (1995; 2002). The Scent of Eros: Mysteries of Odor in Human Sexuality. New York: Continuum Press; 2nd ed. Lincoln NE: iUniverse Press.
Moss, R. L., Dudley, C. A., & Riskind, P. N. (1991). Gonadotropin releasing hormone and human sexual behavior. In C. B. Nemeroff (Ed.), Neuropeptides and Psychiatric Disorders. Washington, D.C: American Psychiatric Press.
