It’s interesting to see how differently people react to children sucking their thumbs and using pacifiers. Children naturally suck their thumbs –often from time they have enough coordination to get their thumb to their mouth. This is a human reflex that babies learn to associate with the pleasure and calming of being fed and held. No wonder it is such a powerful habit that often continues through childhood. Some children have learned to use a pacifier in the same way.
It is a cultural choice that a particular society makes as to when a child should stop this behavior. For some families, thumb-sucking is encouraged and it is not considered a problem for older children to still suck their thumbs or use a pacifier. In other cultures and families, children are expected to stop such behavior as a toddler. Some parents encourage using a pacifier in order to prevent dental problems from thumb-sucking which can happen if a child sucks very forcefully.
Since thumb-sucking is a way of coping with anxiety and calming oneself, you can also try to figure out what triggers the need for this self-soothing. Can you help the reduce the stress the child is experiencing? You can also teach the child other relaxation exercises such as breathing or self-talk. Don’t be punitive. Remedies such as bitter ointments or gloves generally do not work because they cause more stress and don’t offer the child a replacement for the soothing they achieved from thumb-sucking.