Thursday, April 28, 2005

Are children's taste preferences due to nature, nurture, or both? These issues are addressed in a study focusing on a newly discovered gene that controls the perception of bitter taste. Scientists at the Monell Chemical Sense Center in Philadelphia enrolled 143 mothers and their children between 5 and 10 years old for the experiment. All participants had their DNA analyzed to see how many of the "bitter taste" genes they had. People who have two of these genes tend to be sensitive to bitter taste, those who have none are relatively insensitive to bitter tastes, and those with one are in between. The investigators studied both sensitivity to bitterness and preferences for sweetness related to these genes and also how cultural and ethnic differences might modify these responses in adults.

After tasting sweet and bitter substances, the children were told to give what they tasted to Big Bird if it tasted good or to Oscar the Grouch if it tasted bad. Mothers were asked to provide verbal responses after their taste tests. Both children and adults were also asked to name their favorite foods and drinks.

The results showed that:

• Children's responses to bitter tastes correlated well with their genetic endowment.
• Children with the two bitter sensitive genes were more likely to prefer sugar-containing drinks and cereals than those with none, and were less likely to choose milk or water for their favorite drinks.
• Adult preferences for sweet tastes seemed to be less determined by genetics and more by cultural factors such as ethnicity and race.

In addition, mothers who had a different number of "bitter taste" genes than their children were more likely to perceive their child as emotional when they did not respond as the mothers would to their favorite foods. (Pediatrics, vol. 115, no. 2 [Feb. 2005]: e216-222)

It remains - and will remain - the ongoing discussion of human existence: Is our behavior, our shaping, our journey genetically predetermined or do we have the monumental power to influence and shape one another through general socialization? I'm not sure that I have an answer or a suitable opinion at this point. But this much, I do believe...

Espiritus. The breath of Spirit. It lies within and forever remains within us throughout our physical life. Is it genetically based? It is my belief that it is the very spark that fuels the tiniest quark to the grandest human action or deed. It is the source of energy that allows all cerebral circuits to be overridden and causes us to rush into fires and jump off buildings to save a life... to give our very physical life for another.

Understanding why and how we, as humans, come to develop is a noble journey and exploration. The advancement of science continues to and will always amaze me. But what amazes me more is how life - from simply chromosomal soup - knows how to burst forth, divide and multiply and advance. What amazes me more is the origin of human intellect to know right from wrong and the human drive to try to do what is right the majority of the time. Narrow these processes down to "nature or nuture" and it still begs the question, "And from source does the nature or nurture originate?" Espiritus.