Love (scientific views)

From a scientifically testable frame of reference, love is a type of interpersonal relationship where mutual assumption of good faith results in a state of emergence, i.e. constituents individually perceive the group's social evolution as both beneficial and greater than what could be achieved by the sum of the relationship's parts.

Biological sciences such as a evolutionary psychology, evolutionary biology, anthropology and neuroscience have begun to explore the nature and function of love. Specific chemical substances such as oxytocin are studied in the context of their roles in producing human experiences and behaviors that are associated with love.

Overview

Psychologists have created many descriptive theories of love in an effort to understand the full range of experiences and behaviors associated with love. For example, much human behavioral research and research with non-human primates has centered on the importance of parental love for the development of good mental health in infants. [ [http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1868534 Developing a Sense of Safety: The Neurobiology of Neonatal Attachment] by R. M. Sullivan in "Annals of the New York Academy of Sciences" (2003) Volume 1008 pages 122–131.] Romantic love between adults is important in the context of human reproduction. ["Human sexual behavior" by Philip Feldman and Malcolm MacCulloch. Published by John Wiley & Sons. 1980. ISBN:4712767669.] Sociological surveys indicate that romantic love is a universal phenomenon of all human cultures. ["A cross-cultural perspective on romantic love" by W. R. Jankowiak and E. F. Fischer in Ethnology (1992) Volume 31 pages 149–155.] Biological approaches tend to treat love as a brain-generated physiological process like hunger or thirst. ["Love: an emergent property of the mammalian autonomic nervous system" by S. W. Porges in "Psychoneuroendocrinology" (1998) Volume 23 pages 837-861. PMID 9924740.] The physiology of love is studied in relation to the actions of neurochemicals and hormones (such as oxytocin) and it is suspected that some chemicals might act as human pheromones. Modern brain scanning techniques such as MRI can be used to explore which brain regions are involved in the experiences and behaviors associated with love.

Biological theories

From the perspective of evolutionary psychology the experiences and behaviors associated with love can be investigated in terms of how they have been shaped by human evolution. ["Evolutionary psychology: the emperor's new paradigm" by D. J. Buller in "Trends Cogn. Sci." (2005) Volume 9 pages 277-283.] For example, it has been suggested that human language has been selected during evolution as a type of "mating signal" that allows potential mates to judge reproductive fitness. [ [http://psycprints.ecs.soton.ac.uk/archive/00000137/ The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature] by Geoffrey F. Miller in "Psycoloquy" (2001) 12,#8.] Miller described evolutionary psychology as a starting place for further research: "Cognitive neuroscience could try to localize courtship adaptations in the brain. Most importantly, we need much better observations concerning real-life human courtship, including the measurable aspects of courtship that influence mate choice, the reproductive (or at least sexual) consequences of individual variation in those aspects, and the social-cognitive and emotional mechanisms of falling in love." Since Darwin's time there have been similar speculations about the evolution of human interest in music also as a potential signaling system for attracting and judging the fitness of potential mates. [ [http://www.unm.edu/~gfmiller/new_papers2/miller%202000%20music.DOC Evolution of human music through sexual selection] by G. F. Miller in N. L. Wallin, B. Merker, & S. Brown (Eds.), "The origins of music", MIT Press, (2000). pp. 329-360.] It has been suggested that the human capacity to experience love has been evolved as a signal to potential mates that the partner will be a good parent and be likely to help pass genes to future generations. [ [http://www.duke.edu/~haufe/mate.pdf Sexual selection and mate choice in evolutionary psychology] by C. Haufe in "Biology and Philosophy" doi|10.1007/s10539-007-9071-0]

Studies in neuroscience have involved chemicals that are present in the brain and might be involved when people experience love. These chemicals include: nerve growth factor [www.ncbi.nlm.nih.gov/pubmed/16289361] , testosterone, estrogen, dopamine, norepinephrine, serotonin, oxytocin, and vasopressin. ["The neurobiology of love" by S. Zeki in "FEBS Lett." (2007) Volume 581 pages 2575-2579. PMID 17531984 ] Adequate brain levels of testosterone seem important for both human male and female sexual behavior. [ [http://joe.endocrinology-journals.org/cgi/content/full/186/3/411 The endocrinology of sexual arousal] by J. Bancroft in Journal of Endocrinology (2005) Volume 186 pages 411-427.] Dopamine, norepinephrine, and serotonin are more commonly found during the attraction phase of a relationship.Fact|date=October 2007 Oxytocin, and vasopressin seemed to be more closely linked to long term bonding and relationships characterized by strong attachments.

In the February 2006 issue of National Geographic, Lauren Slater's cover page article "Love: The Chemical Reaction" discusses love and the chemicals responsible. In it Slater explains some of the research in the area. The conventional view in biology is that there are two major drives in love — sexual attraction and attachment. Attachment between adults is presumed to work on the same principles that lead an infant to become attached to his or her mother or father.

According to Slater's research, the chemicals triggered responsible for passionate love and long-term attachment love seem to be more particular to the activities in which both participate rather than to the nature of the specific people involved. Chemically, the serotonin effects of being in love have a similar chemical appearance to obsessive-compulsive disorder; which could explain why a person in love cannot think of anyone else. ["Aphrodisiacs past and present: a historical review" by P. Sandroni in "Clin. Auton. Res." (2001) Volume 11 pages 303-307] For this reason some assert that being on a SSRI and other antidepressants, which treat OCD, impede one's ability to fall in love. One particular case:

:"I know of one couple on the edge of divorce. The wife was on an antidepressant. Then she went off it, started having orgasms once more, felt the renewal of sexual attraction for her husband, and they're now in love all over again." (38)

The long-term attachment felt after the initial "in love" passionate phase of the relationship ends is related to oxytocin, a chemical released after orgasm. [Carmichael MS, Humbert R, Dixen J, Palmisano G, Greenleaf W, Davidson JM. (1987) Plasma oxytocin increases in the human sexual response. "J Clin Endocrinol Metab" 64:27-31 PMID 3782434] Moreover, novelty triggers attraction. Thus, nerve-racking activities like riding a roller coaster are good on dates. Even working out for several minutes can make one more attracted to other people on account of increased heart rate and other physiological responses.

Brain scanning techniques such as magnetic resonance imaging have been used to investigate brain regions that seem to be involved in producing the human experience of love. [ [http://jn.physiology.org/cgi/content/full/94/1/327#R48 Reward, Motivation, and Emotion Systems Associated With Early-Stage Intense Romantic Love] by Arthur Aron1, Helen Fisher, Debra J. Mashek, Greg Strong, Haifang Li and Lucy L. Brown in "Journal of Neurophysiology" (2005) Volume 94, pages 327-337.]

See also

*Biological Attraction
*Love
*Love (cultural views)
*Love (religious views)
*Love sickness

References

External links

* [http://iserver.saddleback.cc.ca.us/faculty/jfritsen/articles.html The Science of Love]
* [http://psychclassics.yorku.ca/Harlow/love.htm The Nature of Love (1958)] - Harry Harlow, "American Psychologist, 13, 573-685"
* [http://www.pbs.org/wgbh/aso/databank/entries/bhharl.html Harry Harlow] - A Science Odyssey: People and Experiments