Scientist studying cholesterol metabolism in rabbits found that rabbits who were petted, cuddled, and caressed failed to have high cholesterol levels despite being fed the same high cholesterol diet as another group of rabbits who remained locked in their cages.

In a New York Public Library study librarians instructed to lightly touch (on the hand, writ, arm,or shoulder) every other patron who checked out a book. Those who were touched rated the library twice as efficient as the untouched patrons.

Waitresses and waiters  (or wait persons, to be politically correct) were instructed to lightly touch the shoulder of the diner when the bill was presented. Tips increased 48% when the paying guests were touched.

Conclusions:
Shake hands

Pat people on the back when they have done a job well

Hug more (when appropriate)