Wednesday, January 07, 2009

Looking for Love? Trying Looking in Our Brain and Genes

Imagine this. You are single and sign up with an online dating agency to help you find your "perfect mate". Within a few days a match is found. And the good news is that the person you have been matched to has scored very high on a genetic test for being predisposed to quality romantic relationships! Sound like science fiction? It is, but it may not be long before something like this is a reailty.

The latest issue of Nature has this fascinating article on the neural and genetic components of love. Here is a sample:

... researchers are attempting to isolate and identify the neural and genetic components underlying this seemingly uniquely human emotion. Indeed, biologists may soon be able to reduce certain mental states associated with love to a biochemical chain of events. This has implications for the evolution of human sexuality, and raises important societal issues given our increasing use of genetic tests to screen for certain behaviours, and of drugs to modulate mental processes.

Animal models have greatly aided our understanding of the mechanisms that regulate emotions — particularly for evolutionarily conserved states such as fear and anxiety. These advances have led to pharmaceutical therapies for anxiety, phobias and post-traumatic stress disorders. Such models are also beginning to shed light on love.

We are not alone in being able to form intense and enduring social ties. Take the mother–infant bond. Whether or not the emotional connection between a ewe and her lamb, or a female macaque and her offspring, is qualitatively similar to human motherly love, it is highly likely that these relationships share evolutionarily conserved brain mechanisms. In humans, rats and sheep, the hormone oxytocin is released during labour, delivery and nursing. In ewes, an infusion of oxytocin into the brain results in rapid bonding with a foreign lamb.

....Similarly, in humans, different forms of the AVPR1A gene are associated with variation in pair bonding and relationship quality. A recent study shows that men with a particular AVPR1A variant are twice as likely as men without it to remain unmarried, or when married, twice as likely to report a recent crisis in their marriage. Spouses of men with the variant also express more dissatisfaction in their relationships than do those of men lacking it. For both voles and humans, AVPR1A genetic polymorphisms predict how much vasopressin receptor is expressed in the brain.

The BBC has the scoop on this story here. This research raises many interesting issues to consider, especially for me given that love is the foundation of my perfectionist account of ethics. So much to ponder, so little time!