Bowlbys Theory

Present at birth 

This means give and take. Infants are attached to adults but this is always two way- so the adult has to be attached to the infant.

people who have strong and healthy attachments as an infant, they tend to keep this throughout their whole life.

This means maintaining friendships and reationships easier

Survival of the fittest

passes through genes

whichever person has the strongest/fittest gene is more likely to survive

Bias towards one caregiver, normally the mother. 

Mothers have this if they have twins, they would prefer one to the other, so they dress them alike to put them ( in her mind ) as one.

if an attachment is not made with the child within 2 1/2 years, the child will find it very hard to gain one after that time

any behaviour that encourages a reaction

like hugging or smiling

can be innate (born with it) 

or you can be taught it (by your caregivers) when adults say play nicely 

The drive behind attachment

All children need to be fed, cared for and protected.

Adults develop attachments to help them do this to ensure their genes are passed on