Most children, like most adults need appropriate loving touch. It can actually mean the difference between life and death in some instances; however, there are some children for whom touch is extremely difficult.
Children who have had some traumatic experiences, such as abuse or neglect may have difficulty with touch. Other children with some disabilities, even very mild, may have sensory issues. Touch should not be forced on any child or adult (with the possible exception of occasional appropriate hugs by mothers with their only slightly embarrassed adult sons).
Children with attachment disorders, and sometimes children who have been traumatized can be overly affectionate. Be careful about both situations. Consult a very good well qualified therapist who has extensive knowledge and experience in these specific issues if your child has been traumatized, has attachment difficulties or sensory issues. This child may need a different approach and you may need to both respond to and initiate physical contact in a manner which may be uncommon or different for you.
For most children, when you give them a hug, they will signal you when it’s time to release by their own relaxing or tensing. Honor their signal and release when you feel this change.
Please see the supplemental material linked from below, and feel free to use the Google Scholar and/or Parenting Search Engine below.
Good - Appropriate Touch with Children
Teaching Children Appropriate Touch: Helping Kids Understand Personal Boundaries and Showing Affection
How to Speak Love Language #1: Physical Touch - Parenting Ideas