Psychologists from the University of Wisconsin-Madison came to the conclusion that the nipple inhibits emotional development in infants, preventing them to develop their expression skills in an unconscious age. The researchers conducted three experiments on different age groups - boys 6-7 years, students and elderly men, and found that frequent use of pacifiers interfere to produce emotional expression in children. It is known that all people are consciously or unconsciously imitate the body language and facial expressions of other people.
Mimicry has always been an important tool for teaching young children. At the initial stage, infants do not understand the speech, which is why it is so important to communicate with children using facial expressions and tone of voice. The nipple in the mouth covers the full picture, binds mimics and interferes with the child to reflect emotions that they see. It is known that such difficulties are patients using Botox to fight wrinkles. They are unable to Express full range of emotions his face, as a result are hardly recognize others ' emotions. The world health organization has called for a reduction in the use of nipples and advocates for breastfeeding. Doctors agree that harm nipples more than good, but a negative effect on mental development was observed only when using the nipple during wakefulness child.