[1][3] The term was coined and subsequently developed over the course of four decades, from the early 1940s to the late 1970s, by psychologist John Bowlby in his work on attachment theory.
The central features of the concept of affectional bonding can be traced to Bowlby's 1958 paper, "The Nature of the Child's Tie to his Mother".
From this groundbreaking study, Ainsworth developed different forms of attachment styles that infants display with the people they are close to.
As they embark on childhood, those who maintain secure attachment have an easier time making friends and meeting new people and hold a trustworthy bond with their parents.
Insecurely attached adults tend to act cold and experience many break-ups throughout their life.
[8] Infants and children with avoidant attachment tend to show no preference between their caregivers and the stranger.
In adulthood, those with avoidant attachment have difficulty maintaining relationships due to the inability to display emotions.
These studies have also shown that attachment styles developed in infancy can influence behavior later in life.
Research by Main and Hesse showed that parents who use tactics of fear and assurance contribute to this disorganized form of attachment.
[13] Older couples' deep displays of bonding stem from the sheer longevity of their relationship.
Having shared many lifetimes' worth of experiences together, they have built a solid foundation based on trust, mutual understanding, and acceptance.
[14] The bond between sexual partners is characterized with three components which are reproductive, attachment and caregiver, and they may be more prevalent in certain relationships than in others.
When an attachment is formed on top of the reproductive bond, the male is likely to take on a caregiver role with offspring as well as his mate; which in western culture is usually his wife.
In traditional married couples the level of sexual attachment changes throughout the lifespan of the relationship thus stating that there are other important aspects of the bond between husband and wife.
In western society traditional gender roles are being challenged which is impacting the level of male caregiver attachment to his wife; however there is not a large field of research on the subject.
[13] Non-heterosexual couples are hypothesized to share much of the same attachment components; however there is little research on the subject to draw conclusions from.
Again, these bonds tend to not be as strong as those formed with other kin, but the social aspects of them are essential to development.
The level of bond between kin is often because of shared values, culture, background, and personal experiences.
[15] The results show that infant monkeys spent significantly more time with the terry cloth mother whether she provided nutrients or not.