the.com/unkind
Kindness with the lights off — cruelty's quieter, more respectable cousin.
means Lacking warmth or compassion; behaving in a way that hurts or disregards others' feelings.
from From Old English 'gecynd' (nature, kin) — to be unkind once meant to act unnaturally, against your own kind.
Buried kinshipShares a root with 'kin' and 'kindred.'
Old meaningOnce meant unnatural or against nature.
Soft edgeMilder than cruel, sharper than cold.