Babies first show “stranger anxiety” at between 8 to 10 months of age. As their brains develop rapidly, they also learn social-emotional skills and recognise the identity of “parents”. Thus, they do not trust any other adults that are not “parents”. This phenomenon usually disappears after two years, but they then receive education from adults that they should not trust strangers, or Stranger Danger.
Interestingly, most kidnapping cases are committed by an adult the child knows well.
Another fact related to stranger anxiety is that it is dependent on how close the baby is to its parents. Take the Strange Situation Test developed by Ainsworth as an example:
Put a baby under the age of 12 months and its parent in the same room, then separate the two. Next, send in an adult the baby has never seen before, then after a short while exchange the adult back with the parent.
Normal babies become anxious and agitated when a stranger enters the room, but then they calm down almost immediately as the parent returns. Also, when the parent returns the baby requests to be held, as physical contact represents safety for a baby.
However, a baby that has spent less time with its parents, or a baby with unresponsive parents exhibit a different behaviour. In fact, they become more agitated when the parent returns, and often show avoidance. This is because there has been insufficient bonding between the two.
A more extreme case is of a baby that has been abused. These babies become extremely disorganised and disoriented upon the parent’s return. This is also due to improper socio-emotional development. Babies like these that were not intimately bonded with their parents tend to have trust issues even after development, which may lead to social problems in adulthood.