Harden Not Your Heart

Even those of us who do not read bible passages on a weekly basis are nonetheless familiar with many of them.

There is a phrase that appears in both the Old and New Testament that has long arrested me. I first heard it in a passage from the Passover Haggadah, in connection to the story of the Ten Plagues. The Plagues were supposed to cause Pharaoh to relent, and allow Moses to lead his people out of Egypt, out of oppression. But nine times, Pharaoh changed his mind. In the text, he "hardened his heart."

In the New Testament there is a prominent teaching, "Harden not your heart."

Most of us understand this metaphor to mean a failure to adopt a merciful, compassionate, and understanding attitude. In the 1982, the pop group Quarterflash produced a musical number entitled Harden My Heart to dramatize seething anger that culminates in bulldozers and flamethrowers.

But why that metaphor? Why the metaphor of "hardening the heart"?

Today we know that the heart is a powerful muscle, used to pump blood.

Like any muscle, it can be made hard by mechanically tensing it. Who among us has not "made a muscle" of the biceps and palpated it to see how hard we can make it?

But the heart is not a voluntary muscle like a bicep. What hardens it?

Today most of us can name the neuropeptide that acts to make the heart race like mad, pumping blood in times of stress or danger. We know it as the Fight or Flight Response, mediated by Adrenaline.

And yet as a child, I was mystified by the biblical phrase, "harden the heart" for a reason that most adults of that era would not have been able to explain.

You see, I'm a redhead.

And there is something different about redheads.

For reasons having to do with physiology and cell biology, those of us who have diminished levels of Eumelanin also have correspondingly diminished levels of correlated neuropeptides, including Adrenaline, Serotonin, Dopamine, and Oxytocin.

As a result we tend to be somewhat more mellow, contemplative, and affectionate than the mean population. Think of a Golden Retriever. That's my demeanor.

The key thing here is a diminished store of Adrenaline. I rarely pump Adrenaline, and then only under exceedingly dire circumstances, such as a life-or-death situation (which almost never happens in my laid back life as a semi-retired scholar, researcher, and science educator).

But a lot of people not only experience Adrenaline surges, they actively seek the thrills that produce an Adrenaline rush. And one effect of that is to activate the heart muscles so that they can pump blood like crazy.

It's hard for me to have empathy for someone who is berserking in an Adrenaline-driven rage, because it's not a physiological state that I have any direct experience with.

Oh, sure, I've had my heart-pounding moments, but harnessing that surge of physical energy for Fight or Flight is just so far outside of my normative behavior that it didn't even occur to me to put a fist through a wall (let alone someone's nose).

On the Internet, it's nigh impossible to detect when a correspondent is in an Adrenaline-mediated rage. You can't see their eyes bulge out, or any other physiological manifestation of turning into the Incredible Hulk. Instead, people seem to take on a Jekyll and Hyde character, behavior uncharacteristically idiotic when intoxicated with Adrenaline and other surging neuropeptides (like Dopamine).

When us mellow redheads observe that, we scratch our heads, and mutter WTF???