From Creation Moments
Which sense could be lost with the least threat to your life? Most people consider their sense of sight the most important. While the loss of sight is a terrible tragedy, life can go on. Lose your sense of smell and food will be flavorless, but you can get by. Loss of hearing, too, is a great loss, but the loss can be adjusted to. And few people's lives are threatened by the loss of the sense of taste.
However, if you lose your sense of touch, you lose your sense of pain and therefore any warning that you might be injuring yourself. Unfortunately there are people who have no sense of touch. Sometimes they receive life-threatening injuries because they cannot feel pain.
Science has shown that touching is necessary for life. Newborn animals that are licked by their mothers have a higher resistance to disease. They are also more likely to live to adulthood than newborns who are untouched by their mothers.
Chihuahua pups have a notoriously high rate of death because their mothers are often unwilling to lick them. Lambs will die after birth if their mothers do not lick and nuzzle them. Even human infants who are not lovingly touched enough will suffer from depression, poor sleep, weight loss, poor immunity and, in extreme cases, even death.
References: McCutcheon, M. 1989. The Compass in Your Nose . . .. Los Angeles: Jeremy P. Tarcher. p. 112.
Source: Creation Moments