how much of 'pretty' is wired in, and how much is learned
For a century it was assumed that liking consonance over dissonance was biological — evolved, universal, human. Then McDermott and colleagues (Nature, 2016) tested the Tsimané, an Amazonian society with little exposure to Western music, and found they rated consonant and dissonant chords equally pleasant — while Bolivian city-dwellers and US listeners preferred consonance, the preference scaling with Western exposure. The twist that keeps physics in the story: the Tsimané still disliked acoustic roughness (fast beating between close tones), just not inharmonicity. So the current reading is layered — an aversion to roughness looks broadly shared, while the preference for harmonic consonance appears substantially learned by exposure. And it's a live fight: the nativist camp answers that scale structures look strikingly similar across cultures and that the study inferred exposure rather than measuring it. Treat this as an active seam in the science, not a verdict — what sounds good is part physics, part upbringing, and the argument is over the mixing ratio.
Try it on the neckThis is why a distorted power chord reads as 'heavy' not 'ugly' while a distorted major third turns to mud: distortion is nonlinear, so it manufactures new sum-and-difference tones from every pair of frequencies — a 3:2 fifth's products land back inside the shared harmonic family, while a third's land off it and pile up (the guitar's sharp equal-tempered third makes it worse). The amp is running the roughness experiment for you.
Tsimané rated consonant/dissonant chords equally pleasant; preference scaled with Western exposure — McDermott, Schultz, Undurraga & Godoy, Nature 535 (2016)Aversion to roughness present without preference for harmonicity → consonance preference shaped by familiarity — McPherson et al. (2020); review in Music & ScienceThe nativist rebuttal: cross-cultural similarity of tonal systems; exposure inferred, not measured — Bowling, Hoeschele, Gill & Fitch, Music Perception 35 (2017)