We had an amazing guest on The Health Hub recently, Lydia Denworth, who spoke to us about Affective Touch. Lydia is the author of two acclaimed books of popular science “Toxic Truth: A Scientist, A Doctor and the Battle Over Lead” and “I Can Hear You Whisper: An Intimate Journey through the Science of Sound and Language”. She is a regular contributor to Scientific American and writes the Brain Waves blog for Psychology Today. Her work has also appeared in a wide range of national publications including Newsweek, Time, The Wall Street Journal, The New York Times, and Parents.
Here is a snippet of what we learned.
There are five senses: sight, hearing, taste, smell and touch. Of these 5, what would you say if I told you one can affect children at a molecular level? Would you know which one? If you guessed touch, you would be correct. While it is widely accepted that hugging and cuddling are beneficial in nurturing relationships, especially in infants, it is now believed that a loving touch, a slow caress or stroke, can increase the brain’s ability to construct a healthy sense of self. Who knew a simple touch could pack such a powerful punch?!
In the last few years, neurologists have discovered that we have a specialized neurophysiological system – affective or emotional touch. This system consists of nerve fibers triggered by exactly the kind of loving caress a mother gives her child. These new fibers, which are present only in hairy skin such as the forearm or the back and known as C-tactile (CT), are thought to spark the limbic part of the brain which monitors emotion. A recent study of 94 infants over the span of 5 weeks to 4 ½ years at the University of British Columbia showed consistent differences between high-contact and low-contact children at five specific DNA sites. Two of these sites fall within genes: one plays a role in the immune system and the other is involved in metabolism. This same study revealed that
“children who had been more distressed as infants and received less physical contact had a molecular profile in their cells that was underdeveloped for their age.” 
Touch is the first of our senses to be available to us, as early as in utero. Affective touch is not only physically rewarding, but also has the potential of positive social development. In these times when the lines of acceptable touching seem so blurred, it’s comforting to know that a slow, gentle caress on the arm or back at an early age can set the stage later in life for deciphering what is appropriate versus inappropriate.
So hug your loved ones a little tighter and recognize that you are helping to develop their sense of self as well as their future relationships.