A lot of things change when a woman welcomes a new baby, if not everything. It is said that when a child is born, so is a mother too.

The process of becoming a mother is probably the most significant change a woman can experience in her lifetime, on the physical, psychological, and emotional levels. In anthropology (the study of what makes us humans), the process of becoming a mother is referred to as “matrescence”. Just as adolescence describes a teenager’s passage into adulthood, matrescence describes the transition of a woman into motherhood, a phase during which hormones surge, the body changes, and identity and relationships shift.

For new mothers, some of the starkest changes that they experience have to do with the emotions that come with motherhood – those feelings of overwhelming love and fierce protectiveness, but also constant worry, fear, and anxiety – the sum of which we colloquially refer to as the “maternal instinct”. These emotions, as it turns out, are largely rooted in the physiological reactions that happen in the brain of a woman as she transitions into motherhood

HOW?

Studies show that when women become mothers, the brain’s gray matter – which plays a large role in memory and decision-making –  shrinks in size, which might explain some of the most stereotypically frustrating side effects of giving birth, like that period of forgetfulness during new motherhood, otherwise known as “mommy brain,” and the major mood changes that accompany pregnancy. Whereas the “loss” of this brain material might seem like a bad thing, scientists think that these changes are intended to shift the mother’s focus from relatively unimportant tasks, such as remembering a movie title and allocate it to other parts of the brain that control emotional processing and the ability to understand what someone else wants and needs. 

Indeed, studies comparing brain scans of women before and after giving birth show a significant increase in activity in other areas of the brain such as in the prefrontal cortex, which controls planning, learning and emotional regulation, the parietal lobe, which is related to empathy, and in the temporal lobe, which increases moms’ ability to process emotions and understand her baby’s cues and needs. The size of the amygdala – a set of neurons known to drive emotional reactions like anxiety, fear, and aggression – is also noted to increase in size in the weeks and months following giving birth, which goes to explain why so many new mothers experience serious anxiety and depression.

This happens in addition to a rise in the levels of hormones, such as oxytocin – a.k.a the love hormone – which circulates through a mother’s body making her feel attached to her baby at the most basic cellular level and giving her motivation to continue with her motherly behavior. Just by staring at her baby, the reward centers of a mother’s brain will light up, as shown by several studies.

And so it seems that one reason why mothers can tirelessly deal with feeding, cuddling, and chasing after their children, why they’re the only ones who can heal an aching heart with a hug, why the love of a mother may be the purest form of love we can ever experience, why a child’s connection to their mother is like no other – is the fact that mothers are hard-wired to give love and care, unconditionally. They just simply have superpowers.