Why Love Matters

English poet Samuel Taylor Coleridge once observed that a tiger stays the same whether you imagine it living alone or in a “society” with thousands of other tigers. Either way, a tiger is a tiger. 

But humans are different. We are, in Coleridge’s words, “truly altered” by our relationships with other humans. Without these relationships, we wouldn’t develop qualities like empathy or the ability to read social cues.

Today, we have a name for what Coleridge was describing. We call it the social brain.

The key message in this blink is: The brain evolved in stages, and the social brain developed last.

In everyday speech, we usually refer to “the brain,” but this isn’t quite accurate. We actually have what neuroscientists call a triune brain, or three brains in one. Each of these brains reflects a different stage in our evolution.

In the first stage, we developed a brain similar to that found in reptiles. This simple cognitive setup was based around the brainstem, and supported basic life functions like breathing. 

In the second stage, we developed a mammalian brain around this reptilian core. It allowed for basic emotions, which in turn added new qualities, like the ability to nurture offspring. 

In the third and final stage, we developed the cerebral cortex in the outer layers of the brain. This is where the social brain – the thing that makes humans human – formed.

The social brain is activated when we control our emotions, follow social cues, and experience empathy. It also allows us to go beyond instinctive ways of behaving.

So, instead of simply experiencing primal emotions like fear, anger, or satisfaction, we can diversify these feelings into more complex intermediary states, like sadness, shame, guilt, love, pleasure, happiness, and more. Metaphorically speaking, while most mammals see the world in black and white, our social brain allows us to see it in technicolor.

Here’s where things get interesting. A newborn baby’s brain has several systems to ensure survival. It has a functioning nervous system that makes it possible for her to breathe, a visual system that lets her track movement, and a core consciousness in the brainstem that enables her to react to sensory stimuli like temperature. But the social brain is missing. And, as we’ll see in the next blink, it only begins developing after a baby is born.