Have you used or heard the expression "just a touch?" It usually means just a small amount, as in "the sauce needs just a touch more salt" or "yes, I'd like just a touch more coffee." I imagine that there are places in the world where this equation of touch with a small amount would make no sense at all. It makes sense here and now because we rigorously limit the experience we have with touch.
Ironically, the more we limit our ability to touch each other through social rules, the more we learn that touch is as important to our development as all our other senses. For many years, we have known that babies deprived of touch do not thrive. Increasing numbers of studies with premature infants have established that touch helps them grow and mature. Other studies have explored the effects of touch-deprivation on seniors. Throughout our life, it seems, we do better when we are able to make use of all of our senses, including our sense of touch.
What is the difference between touching things and touching people? Skin to skin contact is important for babies. It's interesting to think about all the things they are calibrating as they are touched. Like all the sensory systems, touch is multi-dimensional: it gives us information about pressure, temperature, texture, rhythm, and electrical charge. And this information changes quickly. Think of a time you were walking and holding hands with someone. As you enter into that experience, notice all the changes in your hand as you move forward. Even if the touch is held, it is different.
Most of the time, touch in our experience is light and quick: we hug or kiss socially, shake hands, or bump into each other as we reach for the salt across the table. It is "just a touch." As you move through your day today, notice when you touch, how long it lasts, and what would change if you had no sense of touch.
Notice, too, the effects of just a touch more salt on your food. Precise adjustments mean small variations for big effects.