Through no other sensory channels can humans convey positive emotional signals among themselves as quickly and unmistakably as through touch. The spectrum ranges from affection, forgiveness and joy to approval, praise and appreciation. Photo: dpa
We do it when we see a friend or loved one after a long separation. And when we comfort someone. Or when we're at someone's sickbed and simply want to let them know we're there for them.
It can be a warm embrace, a fleeting caress on an arm, or holding a hand: A touch says more than a thousand words.
Touch is the first sense that babies develop. They feel the amniotic fluid around them in the womb, and they respond to their mother touching her belly.
Even before they're born, nature teaches them a lesson: "Something that touches my body, and is soft and warm, is good for my body," says psychologist and author Martin Grundwald, founder of the Haptic Research Laboratory at the University of Leipzig in Germany.
It's a product of evolutionary biology. Growth and maturation processes are more or less directly tied to physical contact, notes Grunwald, who for years has been doing research on why we can't live without the sense of touch. Nature has ensured that humans, as "altricial mammals", can only thrive when they live in a social community.
"We need these tactile stimuli our entire life, and they're really existential in early childhood," he says. "Whether you're an infant or an adult, a lack of human touch leaves deep emotional scars that in infancy can even be fatal."
Through no other sensory channels can humans convey positive emotional signals among themselves as quickly and unmistakably as through touch. The spectrum ranges from affection, forgiveness and joy to approval, praise and appreciation.
Even tiny deformations and minimal temperature changes of the skin have effects on our brain. "Not only minutes-long massages alter neurobiological activity," remarks Grunwald, but even light tactile stimuli lasting merely seconds have been shown to impact psychological processes.
The sense of well-being you get when someone embraces or cuddles you – and you them – isn't just a feeling. It's actually measurable, for example in the form of oxytocin in your blood and saliva. Often called the "love hormone" due to its association with pair bonding, oxytocin causes the adrenal cortex to secrete less of the stress hormone cortisol. Heart rate slows, blood pressure sinks and muscles relax.
"But it's not just about purely psychological effects," says biopsychologist Dr Sebastian Ocklenburg, whose research specialisation happens to be hugging. He points to studies showing that hugging has beneficial health effects as well.
"People who embrace more often have a lower risk of contracting colds," he says, since stressors strongly influence the immune system.
Not every touch is automatically felt to be positive though, and certainly not by people suffering from trauma. Ocklenburg has even observed what he calls a certain "hug fatigue." An embrace from someone you don't particularly like is probably unpleasant, as is embracing, "out of social pressure", a new friend or acquaintance you hardly know.
How much physical contact do people need? It depends a lot on their personality, whether they're introverted or extroverted, and on their individual desires. And on the relationship they may be in.
"The closer you are to someone [emotionally], the stronger your biological reaction to tactile stimuli [from that person] is," Grunwald says.
Ocklenburg reports that longer embraces trigger the release of more pair-bonding hormones. An "average embrace" lasts just three seconds, he says, adding: "Ten seconds is long!"
"So that their relationship lasts as long as possible," Grunwald recommends that couples embrace five times daily. – dpa/Katja Sponholz
