Prison Chaplain praying with prisoners. Physical contact which is compassionate - neither sexual nor violent, but welcome expression of affection - is rarely experienced in prison. The guard is there to maintain safety and enforce the rules.
For infants, lack of physical stimulation by way of pleasant skin-to-skin contact is detrimental, and will lead to a condition called "failure to thrive". Infants need stimulation, and children continue to need compassionate contact at those times when it is agreeable to them.
As adults, we never outgrow our need for a diet of compassionate contact. Holding / being held, when if seems appropriate, initiate biochemical reactions known to be beneficial to our health. We live "not by bread alone".
(image by stevemccurry.files.wordpress.com)