Examples of physical intimacy include being inside someone's personal space, holding hands, hugging, kissing, caressing and sexual activity.
Several forms of romantic touch have been noted including holding hands, hugging, kissing, cuddling, as well as caressing and massaging.
Most people partake in physical intimacy, which is a natural part of interpersonal relationships and human sexuality, and research has shown it has health benefits.
[6] Some forms of physical touch among monkeys and apes serve multiple functions, including cleaning, treatment of a lice influx or infection and social grooming.
[8] One study has shown that there is generally a higher level of physical intimacy allowed between immediate family members than between second-degree relatives.
Humans experience touch as early as fetal development, when the fetus begins receiving sensory information from coming in contact with the mothers' abdominal wall.
In addition to necessary functions like breastfeeding, touch is also used to soothe and calm babies or with skin-to-skin contact called "kangaroo care".
[11] Vision and auditory senses are limited in infancy and babies are introduced to their world primarily through touch and are able to distinguish between temperature and texture.
When a partner or friend is not available at such a time, some people satisfy this need for human contact in a crowded venue, such as a bar, nightclub, rock concert, street festival, etc.
In private, people in an intimate relationship or who are familiar with each other may be at ease with physical contact and displays of affection, which may involve: Bonding through intimate, non-sexual contact between platonic friends and family members includes, but is not limited to, holding hands, hugging, cuddling, and kissing on the cheeks.
[18] Peoples living nearer to the equator (Mediterranean, central and South America, Islamic countries) tend to have high-contact social norms, whereas countries further from the equator tend to be lower contact (northern Europe, North America, northeast Asian).
[19] The term "skinship" (スキンシップ, sukinshippu) originated as a pseudo-English Japanese word (wasei-eigo), which was coined to describe the intimacy, or closeness, between a mother and a child.
[20][21][22] Today, the word is generally used for bonding through physical contact, such as holding hands, hugging, or parents washing their child at a bath.
[24] According to Scott Clark, author of a study of Japanese bathing culture, the word is a portmanteau combining "skin" with the last syllable of "friendship".
[31] Primates tend to groom each other equal amounts of time or with the expectation that they will be reciprocated with defense in a dangerous situation.
[33] It does this not by offering a direct exchange of benefits, but rather by creating the psychological environment that allows support to be traded mutually.