The mammalian brain can host different modes of fear, depending on the kind of threat it is processing.
If I were a capybara therefore, I wouldn’t be fearless. I’d be exquisitely discriminating.
I would instinctively know that crocodiles don't attack every moving object. They conserve energy to strike only under certain conditions.
A crocodile basking on the riverbank nearby therefore represents only a statistical risk to me.
My crocodile isn’t patient because it enjoys waiting. It waits because evolution has taught it that patience is usually the highest-return strategy. Over millions of years, I’ve evolved an equally remarkable ability to calibrate the risks the crocodile’s strategy presents to my continued existence.
To me, if the crocodile's posture, location and behaviour don't fit the familiar pattern that says attack, there’s little value in shifting my body into an expensive state of alarm as I bask alongside these reptiles.
Chronic vigilance is metabolically expensive; i.e. buggering. I would become tired, less efficient and likely more vulnerable.
Instead, I make a probabilistic assessment; i.e. take a punt, resist the fear that I may have misread the signals, and remain in a low-cost, chill, physiological state until the evidence changes.
The appearance of a stalking jaguar on the scene would rapidly change things.
This crosses the threshold from potential to imminent threat, and my nervous system instantaneously shifts from low calorie-burning vigilance to a completely different operating mode: sympathetic activation (aka, shitting bricks), adrenaline, elevated blood pressure and rapid decision-making.
If I panicked at every crocodile, I would quickly exhaust myself and become easier prey. If I ignored even one jaguar, the result would be exactly the same but on a much shorter timescale.
Evolution therefore rewards fear that is calibrated to the situation, not fear at its maximum intensity. In the end, that calibration keeps me alive without requiring a single moment of conscious thought.
And this, to me, is the metaphoric aspect of the capybara's reputation for being "chill". It is not so because it underestimates danger. It is relaxed because millions of years of evolution have taught it which threats deserve a response, and which do not.
That strikes me as an elegant definition of wisdom.
And that is why I want to be a capybara. Because I want to sit next to a crocodile.