An abundance of colourful and round or curved shapes make us feel joyful.
Color, in a very primal way, is a sign of life, a sign of energy. And the same is true of abundance. We evolved in a world where scarcity is dangerous, and abundance meant survival. So, one confetto — which happens to be the singular of confetti, in case you were wondering — isn’t very joyful, but multiply it, and you have a handful of one of the most joyful substances on the planet. … They put people into fMRI machines, and they showed them pictures of angular objects and round ones. And what they found is that the amygdala, a part of the brain associated in part with fear and anxiety, lit up when people looked at angular objects, but not when they looked at the round ones. They speculate that because angles in nature are often associated with objects that might be dangerous to us, that we evolved an unconscious sense of caution around these shapes, whereas curves set us at ease.