Psychologists have long understood the importance of early interpersonal relationships in child development. Several different branches of psychology—including psychoanalysis, attachment theory, and even cognitive therapy—explain personality development in terms of the profound impact of early interpersonal experience. While our understanding of the neurobiology behind these observations is relatively young, we are slowly gaining a richer understanding of how these potent early experiences shape the brain. For one, there is suggestion that representations of early childhood relationships are processed in the superior medial pre-frontal cortex.

Once these representations have been encoded, it is hard to change them. In this way, our view of relationships become somewhat hardwired. It has also been suggested that the emotional tone of early childhood experiences is preserved in the underlying neural circuitry. More specifically, neural circuits underlying positive emotions are strengthened or weakened depending on the degree of positive emotion experienced in childhood. Further, the circuits related to the stress response, particularly the HPA axis, are strongly influenced by the degree of stress experienced during childhood. Over time, this affects the flexibility and resilience of the body’s stress response. We all know people who are entirely overwhelmed by stress. Their stress reactions are easily triggered and they can only calm down with difficulty. In some cases, this might be the result of abnormal levels of stress during childhood.