More about Smells/touch:

My wife used to be able to tell when one of our daughters was sick, just by smelling them, and still is while working as a pre-school teacher.

Two fascinating books on the subjects; "The Perfume", by Patrick Suskind

"'Touching"", by Axel Mantagu.

Should be read at all Nursing/Medical/Social Workers/ schools, and of course, practiced!

Last, but not least, the "scientific"' evidence:

"'The neuropsychologist James W. Prescott has performed a startling cross-cultural statistical analysis of 400 preindustrial societies and found that cultures that lavish physical affection on infants tend to be disinclined to violence. Even societies without notable fondling of infants develop nonviolent adults, provided sexual activity in adolescents is not repressed. Prescott believes that cultures with a predisposition for violence are composed of individuals who have been deprived—during at least one of two critical stages in life, infancy and adolescence—of the pleasures of the body. Where physical affection is encouraged, theft, organized religion and invidious displays of wealth are inconspicuous; where infants are physically punished, there tends to be slavery, frequent killing, torturing and mutilation of enemies, a devotion to the inferiority of women, and a belief in one or more supernatural beings who intervene in daily life. 

Prescott writes:

“The percent likelihood of a society becoming physically violent if it is physically affectionate toward its infants and tolerant of premarital sexual behavior is 2 percent. The probability of this
relationship occurring by chance is 125,000 to one. I am not aware of any other developmental variable that has such a high degree of predictive validity." 

Infants hunger for physical affection; adolescents are strongly driven to sexual activity. If youngsters had their way, societies might develop in which adults have little tolerance for aggression, territoriality, ritual and social hierarchy (although in the course of growing up the children might well experience these reptilian behaviors). If Prescott is right, in an age of nuclear weapons and effective contraceptives, child abuse and severe sexual repression are crimes against humanity. More work on this provocative thesis is clearly needed. Meanwhile, we can each make a personal and noncontroversial contribution to the future of the world by hugging our infants tenderly.

(Cited by Carl Sagan in “Cosmos”,Ch. 13, pg. 274; Ballantine Books, 1985)